Polyploid hybrid breeding

Abstract

The present invention relates to a breeding scheme for the production of polyploid seeds, plants, or plant parts in which cycles of meiosis, gamete mating, and selection are used for interpopulation improvement of ancestral lines, and sexual polyploidization occurs during hybrid production by inducing clonal gametogenesis in the parents to be crossed. Reciprocal recurrent selection can be used to inform the selection of candidate lines that are either advanced to gene editing or genetic modification systems or crossed and selected to induce clonal gametogenesis by arresting meiotic recombination and chromosome reduction. Crosses of parent plants with clonal gametes are planned and executed based on predicted heterosis performance at the ploidy level. The end product is a uniform population of hybrid polyploid seeds, or derivatives thereof, that possess the complete nuclear genomes of both parents. In some instances, the method is used to produce plants that produce seedless fruit.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 423,765, filed November 8, 2022, U.S. Provisional Application No. 63 / 423,768, filed November 8, 2022, U.S. Provisional Application No. 63 / 497,670, filed April 21, 2023, and U.S. Provisional Application No. 63 / 461,174, filed April 21, 2023, each of which is incorporated by reference herein in its entirety.

[0002] Electronic Sequence Listing Reference The contents of the electronic sequence listing (197072000140seqlist.xml; size: 523,525 bytes; and creation date: November 7, 2023) are incorporated herein by reference in their entirety.

[0003] The present invention relates generally to the field of agricultural science and specifically to crop improvement and systems for breeding novel hybrid polyploid plant cultivars. The present invention also relates to population improvement methods for desirably altering the genetic composition of diploid breeding populations to enhance the production of uniform hybrid polyploid seeds, plants, and plant parts suitable for cultivation. The present invention further relates to plant material obtained by this process. [Background technology]

[0004] Population growth, the desire to reduce the environmental impact of agriculture, and consumer food preferences are ensuring a constant demand for improved crop varieties. Crop breeding has been used for millennia as a method to improve crop characteristics, yield, and robustness to environmental pressures. Despite increases in crop yields in the 20th century, crop yields have begun to plateau in recent decades, indicating the need for improved breeding methods (e.g., Rizzo (2021). Climate and agronomy, not genetics, underpin recent maize yield gains in favorable environments. Proceedings of the National Academy of Sciences 119(4):e2113629119). In some staple and horticultural crops, the most widely grown cultivars are polyploids. For example, the most popular and widely grown potato cultivars are autotetraploids, and the Cavendish banana, which accounts for approximately half of global banana production, is a triploid. This creates significant complexity in breeding such varieties due to the high inefficiency of artificial selection in polyploid plant species and the need for vegetative propagation of such varieties, which in some instances is less desirable than seed-based propagation. For example, Cavendish bananas are seedless triploids and must be propagated by vegetative propagation of identical clones. The resulting lack of genetic diversity in banana production makes this crop highly vulnerable to disease outbreaks and other environmental stresses. For such polyploid crops, there is an even greater need for innovative breeding techniques to develop improved varieties.

[0005] Hybrid crops are widely cultivated and favored because they tend to exhibit stronger growth, higher yields, and resilience to environmental stressors compared to their inbred or open-pollinated counterparts. This phenomenon, known as heterosis or "hybrid vigor," reflects the tendency of hybrid plants to exhibit superior quality due to extensive heterozygosity in the plant's genome. Hybrid seeds are usually produced by single crossing a fully inbred parent plant with a different set of alleles, resulting in a biallelic hybrid plant with two sets of alleles (also known as haplotypes) that contribute to heterosis. As a further extension of the heterosis mechanism, polyploid crops can exhibit progressive heterosis, for example, additional heterosis in a multiallelic double-cross tetraploid hybrid plant that is not found in its biallelic single-cross tetraploid parent or its more inbred grandparent. Progressive heterosis has been reported in many tetraploid species, including alfalfa, potato, and tetraploid maize (Gallais, 1984). An analysis of heterosis vs. inbreeding effects with an autotetraploid cross-fertilized plant: Medicago sativa L. Genetics 106, 123-137; Groose et al., 1989). Progressive heterosis in autotetraploid alfalfa: studies using two types of inbreds. Crop Sci. 29, 1173-1177; Mok and Peloquin, 1975. Breeding value of 2n pollen (diplandroids) in tetraploid x diploid crosses in potatoes. Theor. Appl. Genet. 46, 307-314; Washburn et al., 2013. Polyploids as a ''model system'' for the study of heterosis. Plant Reprod 27:1-5;Washburn et al.2019).Gradual heterosis in genetically defined tetraploid maize (J Genet Genomics. 46(8):389-396) has resulted in increased aboveground biomass and several other agronomically desirable traits. However, it is not feasible to utilize gradual heterosis with current breeding techniques while producing a uniform population of true breeding seeds due to the need to cross heterozygous single-cross parents to produce double-cross polyploid hybrids.

[0006] While fruit development in most crops depends on signals from developing seeds to stimulate growth, certain crops can develop fruit in the absence of viable seeds. This phenomenon, known as parthenocarpy, can take various forms. While the mechanism of parthenocarpy varies among crops, one common feature among seedless cultivars is the combination of parthenocarpy with either self-incompatibility and prevention of cross-pollination or complete or near-complete sterility of pollen and / or egg cells. In parthenocarpic crops, low gamete viability nearly guarantees seedless fruit production and is usually achieved by creating triploid plants obtained by crossing between a homozygous diploid pollen source plant and a homozygous tetraploid maternal plant. The primary mechanism responsible for low gamete viability in triploid plants is chromosome nondisjunction. Among other reasons, this can occur because three homologs of each chromosome join and cross over during the first meiotic division, forming a trivalent chromosome. The resulting chromosome segregation of each trivalent into two daughter nuclei is random, making it highly unlikely that a sufficient number of viable, genetically balanced gamete cells can be generated at the end of meiosis. Although they produce highly desirable seedless fruits, triploid systems have several drawbacks. Triploid seeds often exhibit viability issues due to atypical maternal and paternal genome contributions to the endosperm genome. In normal diploid crosses, the embryo is diploid with a triploid endosperm due to a double fertilization process in which pollen sperm cells fuse with the two polar nuclei of the female gametophyte to form the endosperm (2:1 maternal genome:paternal genome contribution). In contrast, crosses between a diploid pollen source plant and a tetraploid mother result in desirable triploid embryos with a pentaploid endosperm (4:1 maternal genome:paternal genome contribution). This ratio of maternal genome to paternal genome contributions to the endosperm results in abnormal seed development and often reduced viability. Another major drawback of triploid systems is that to produce a uniform population of triploid seeds, the tetraploid and diploid parents must be highly homozygous, which limits the number of haplotypes in these individuals to two. Previous studies have established a method that allows plant geneticists to arrest meiosis in plants and replace it with a mitotic-like division in germline cells, resulting in the formation of clonal gametes containing the complete, unrecombined genomes of the parents. The method, known as MiMe (Mitosis instead of Meiosis; d'Erfurth et al. 2009. Turning meiosis into mitosis. PLoS Biol 7, no. 6: e1000124.), is achieved by triple knockout of three genes encoding gene products involved in meiosis: (1) components of sister chromatid cohesion during meiotic division I, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through meiotic division II. Although the technology for MiMe is well developed, commercial development of MiMe has only begun in a select few applications (see, e.g., US20190098858A1, US20120042408A1, and US10883112B2). These current applications of MiMe under development focus solely on the production of apomixis seeds from diploid plants. However, the application of MiMe to develop new and improved breeding techniques for plants at the polyploid level, including polyploid parthenocarpic plants, has yet to be realized. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2019 / 0098858 [Patent Document 2] US Patent Application Publication No. 2012 / 0042408 [Patent Document 3] U.S. Patent No. 10,883,112 [Non-patent literature]

[0008] [Non-Patent Document 1] Rizzo(2021).Climate and agronomy,not genetics,underpin recent maize yield gains in favorable environments.Proceedings of the National Academy of Sciences 119(4):e2113629119 [Non-patent document 2] Gallais.(1984).An analysis of heterosis vs.inbreeding effects with an autotetraploid cross-fertilized plant:Medicago sativa L.Genetics 106,123-137 [Non-patent document 3] Groose et al.1989.Progressive heterosis in autotetraploid alfalfa:studies using two types of inbreds.Crop Sci.29,1173-1177 · Mok and Peloquin.1975.Breeding value of 2n pollen (diplandroids) in tetraploid x diploid crosses in potatoes.Theor.Appl.Genet.46,307-314 [Non-patent document 4] Washburn et al.2013.Polyploids as a ``model system'' for the study of heterosis.Plant Reprod 27:1-5 [Non-Patent Document 5] d'Erfurth et al.2009.Turning meiosis into mitosis.PLoS Biol 7,no.6:e1000124. Summary of the Invention [Means for solving the problem]

[0009] Provided herein are novel methods for breeding polyploid plants and genetically uniform plant populations that apply MiMe in innovative ways to accelerate breeding and produce plants or plant populations that are very difficult or simply cannot be produced by conventional breeding.

[0010] In particular, certain methods utilize the production of clonal gametes to open up the possibility of progressive heterosis in polyploid crop breeding. First, a diverse set of plant lines of a given ploidy is obtained, improved using conventional breeding methods, and organized into heterosis groups based on the predicted heterosis performance of their haplotypes when combined into plants of higher ploidy. Candidate lines containing a total of three or more haplotypes are then selected from the set of plant lines, and one or more candidate lines are induced to form clonal gametes using methods such as MiMe. The clonal gametes are then crossed (e.g., with other gametes, such as clonal gametes, haploid gametes derived from fully inbred individuals, or other types of unreduced gametes that result in three or more haplotypes) to produce a homogenous population of multi-allelic polyploid seeds containing three or more haplotypes of the candidate line. The polyploid seeds are then grown, the plants evaluated for desirable traits in a breeding program, and the heterosis performance of the haplotypes carried by the plants used to guide line breeding and selection in additional rounds of breeding. Representative embodiments of these methods are shown in Figures 16-24C. This method allows for the first time the production of genetically uniform seed of crops containing three or more haplotypes for many species, thus enabling the practical application of progressive heterosis in polyploids.

[0011] Certain related methods provided herein utilize the production of clonal gametes to unlock the potential of gradual heterosis in the breeding of seedless polyploid crops, including parthenocarpic crops. The methods can be applied to the breeding and production of genetically uniform populations of polyploid seeds that result in seedless plants, thereby providing advantages including, but not limited to, a means for manipulating source-sink carbon fluxes in root and tuber crops, utilizing gradual heterosis in breeding improved cultivars of parthenocarpic fruit crops, and producing uniform populations of parthenocarpic fruit crop seeds. In such methods, candidate lines, which may collectively contain two, three, four, or more haplotypes, are selected, and the two or more candidate lines are induced to form clonal gametes by methods such as MiMe to produce two MiMe parent plants, each carrying MiMe alleles conferring clonal gametogenesis at two or more MiMe loci on each set of chromosomes. MiMe parent plants are selected such that a) the wild-type (non-MiMe) allele of the first MiMe parent partially complements the MiMe allele that confers clonal gametogenesis in the second MiMe parent, and vice versa, and b) the MiMe parent plants have at least one MiMe locus that is similar to the MiMe allele at that locus on all sets of chromosomes. The clonal gametes are then crossed to produce a homogeneous population of multiallelic polyploid seeds containing two, three, or more haplotypes of candidate lines that, due to the genotype of the MiMe parent plants, have only MiMe alleles at one or more MiMe loci on all sets of chromosomes and at least one non-MiMe allele at all other MiMe loci. Thus, the polyploid seed population has neither a normal meiotic phenotype nor a clonal gametogenesis phenotype, resulting in nonviable gametes and seedless plants. The polyploid seeds are then grown, the plants are evaluated for desirable traits in a breeding program, and the heterosis performance of the haplotypes contained by the plants is used to guide the breeding and selection of lines in additional rounds of breeding. Representative embodiments of these methods are shown in Figures 16-24C.This method allows for the first time for the production of genetically uniform seeds of crops containing three or more haplotypes that, upon germination, produce plants that produce nonviable gametes for many species, thus enabling the practical application of progressive heterosis in polyploids, including parthenocarpic crops. Additionally, this method provides an alternative to vegetative propagation of seedless, parthenocarpic fruit crops by enabling the production of true seed populations of improved parthenocarpic fruit crop hybrids, thereby addressing the long-felt need for increased genetic diversity in such crops.

[0012] In one aspect, the present disclosure provides a population of polyploid seeds comprising three or more haplotypes of plants of the same or closely related species, wherein at least 50% of the population of polyploid seeds is genetically uniform, and the population was obtained from a single plant or set of plants, such as a set of F1 hybrids. In some embodiments, the present disclosure provides a population of polyploid seeds comprising a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise three or more haplotypes of plants of the same or closely related species, and the population was obtained from a single plant or set of plants, such as a set of F1 hybrids. The polyploid seeds (e.g., the subpopulation of genetically uniform seeds) can be, for example, triploid, tetraploid, pentaploid, hexaploid, hexaploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds is genetically homogeneous. In certain embodiments, the population of polyploid seeds has an average pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient. In certain embodiments, the population of polyploid seeds comprises a subpopulation of genetically homogeneous polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain embodiments, each pair of seeds in a genetically uniform polyploid seed subpopulation has at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% pairwise identity as measured by the Jaccard similarity coefficient. In certain embodiments, the polyploid seeds (e.g., a genetically uniform seed subpopulation) comprise four or more haplotypes of plants of the same or closely related species. In some embodiments, germination of seeds from a polyploid seed population or a genetically uniform polyploid seed subpopulation results in sterile plants that produce nonviable gametes, seedless fruit, or a combination thereof.Polyploid seed populations include, but are not limited to, potatoes, corn, bananas, blueberries, blackberries, watermelons, cantaloupes, tomatoes, tomatillos, peppers, eggplants, grapes, oranges, lemons, limes, grapefruit, cucumbers, squash, gourds, pumpkins, apples, pears, kiwis, pomegranates, mangoes, guavas, papayas, avocados, stone fruits, dates, figs, alfalfa, tobacco, cotton, clover, and figs. Goats, currants, cranberries, gooseberries, boysenberries, raspberries, artichokes, beets, potatoes, sweet potatoes, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yams, radishes, horseradish, turnips, parsnips, rutabaga, yucca, corn, onions, shallots, leeks, radishes, garlic, chives, peanuts, asparagus, sugarcane, and cucumbers. Mackerel, Brussels sprouts, cabbage, collards, kale, lettuce, Swiss chard, spinach, bok choy, okra, cashew nuts, pineapple, celery, oats, birch, rapeseed, mustard, tea, hemp, safflower seeds, cedar, eucalyptus, fir, soybean, sunflower, hemlock, rubber tree, kenaf, barley, hops, walnut, larch, lentils, flax, ryegrass, maple, miscanthus, basil, olive, rice, millet, shepherd's purse, green beans It may be from any plant species, including beans, kidney beans, ground cherries, pine, pistachio nuts, peas, turfgrass, poplar, apricots, plums and prunes, almonds, nectarines, peaches, cherries, roses, brambleberries, rye, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, wheat, broad beans, cowpeas, ginger, kohlrabi, broccoli, and cauliflower.

[0013] In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in reduced expression of one or more, two or more, or three or more MiMe loci. The seeds may comprise one or more genetic modifications that result in reduced expression of MiMe loci, including, but not limited to, REC8, OSD1, CYCA1, TDM1, PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, JASON, PC1, PC2, and FC. In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in altered activity of one or more, two or more, or three or more MiMe components. In some embodiments, altered activity includes, for example, dominant-negative mutants, constitutively active mutants, or null mutants of one or more MiMe components. In one embodiment, the polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In another embodiment, the polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in reduced expression of OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In another embodiment, the polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in reduced expression of PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet another embodiment, the polyploid seeds (e.g., a subpopulation of genetically uniform seeds) comprise one or more genetic modifications that result in reduced expression of PS1, JASON, or a combination thereof. The polyploid seeds may comprise genetic modifications at any combination of the MiMe loci described herein.The one or more genetic modifications may include, but are not limited to, modification of an enhancer at the MiMe locus, modification of a promoter at the MiMe locus, modification of a coding region at the MiMe locus, modification of the methylation status of the MiMe locus, expression of a repressor protein that targets DNA or mRNA at the MiMe locus, and expression of an RNA interference construct that targets mRNA from the MiMe locus.

[0014] In certain embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype including MiMe alleles that confer reduced expression of one or more MiMe loci for each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression during the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In other embodiments, a polyploid population or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first, second, and third MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations, the one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet additional variations, the one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0015] In certain embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype including MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component. In other embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations, the one or more MiMe loci of a component of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations, the one or more MiMe loci of a component of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0016] In certain embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds comprises (i) at least first and second haplotypes comprising one or more MiMe alleles, each conferring reduced expression of one or more MiMe loci of each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are (1) components of sister chromatid cohesion during meiotic division I, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of meiotic division. and (ii) at least a third haplotype comprising (a) a MiMe allele that confers decreased expression of a MiMe locus of a component of sister chromatid cohesion during meiosis I, or (b) a MiMe allele that confers decreased expression of a MiMe locus of a component of progression during meiosis II. In some variations, one or more MiMe loci of a component of sister chromatid cohesion during meiosis I comprise REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet additional variations, the MiMe loci of components of progression during meiosis I of the third haplotype are PS1 or JASON. In yet additional variations, the one or more MiMe loci of components of progression during meiosis II of the first and second haplotypes comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In yet additional variations, the locus of components of progression during meiosis II of the third haplotype is OSD1, CYCA1, TDM1, PC1, PC2, or FC.

[0017] In certain embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has (i) at least first and second haplotypes, each comprising one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first and second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and wherein each of the first MiMe component and the second MiMe component are different MiMe components, and (ii) at least a third haplotype comprising (a) a MiMe allele that conferred reduced expression of a MiMe locus of a component of progression during the first division of meiosis, or (b) a MiMe allele that conferred reduced expression of a MiMe locus of a component of progression during the second division of meiosis. In some variations, one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations, one or more MiMe loci of components of progression through meiosis I of the first and second haplotypes include PS1, JASON, or a combination thereof. In yet additional variations, the MiMe locus of components of progression through meiosis I of the third haplotype is PS1 or JASON. In yet additional variations, the MiMe locus of components of progression through meiosis II of the third haplotype is OSD1, CYCA1, TDM1, PC1, PC2, or FC.

[0018] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0019] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0020] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0021] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0022] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0023] In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) only MiMe alleles at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, a population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0024] In some embodiments, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype including (i) an os allele (wherein the subpopulation of genetically uniform polyploid seeds is homozygous for the os allele), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes: (i) an os allele (wherein the subpopulation of genetically uniform polyploid seeds is heterozygous for the os allele); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0025] In some embodiments, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a complete MiMe genotype that includes (i) a ps allele (wherein the subpopulation of genetically uniform polyploid seeds is homozygous for the ps allele) and (ii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci contains one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partial MiMe genotype that includes (i) a ps allele (wherein the subpopulation of genetically uniform polyploid seeds is heterozygous for the ps allele), and (ii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci includes one or more genetic modifications that result in reduced expression of SPO11-1).

[0026] In another aspect, the present disclosure provides a population of polyploid seeds having a partially complemented MiMe genotype including (a) only a MiMe allele at one or more MiMe loci of a first MiMe component, and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of a second MiMe component, wherein at least 50% of the population of polyploid seeds is genetically homogeneous, and the population was obtained from a single plant or a set of plants, such as, for example, a set of F1 hybrids. In some embodiments, the present disclosure provides a population of polyploid seeds comprising a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, and (b) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the second MiMe component, wherein the population was obtained from a single plant or a set of plants, such as a set of F1 hybrids. The polyploid seeds (e.g., the subpopulation of genetically uniform seeds) can be, for example, triploid, tetraploid, pentaploid, hexaploid, hexaploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds is genetically homogeneous. In certain embodiments, the population of polyploid seeds has a mean pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient.In certain embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain embodiments, each pair of seeds in the subpopulation of genetically uniform polyploid seeds has a pairwise identity of at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient. In some embodiments, the partially imputed genotype comprises only MiMe alleles at one or more MiMe loci of the third MiMe component. In other embodiments, the partially imputed genotype comprises one or more MiMe alleles and one or more non-MiMe alleles at the first MiMe locus of the third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at the second MiMe locus of the third MiMe component. In certain embodiments, the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component.

[0027] In another aspect, the present disclosure provides a population of polyploid seeds having a partially complemented MiMe genotype including (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the second MiMe component, wherein at least 50% of the population of polyploid seeds is genetically homogeneous, and the population was obtained from a single parent plant or set of plants, such as, for example, a set of F1 hybrids. In some embodiments, the present disclosure provides a population of polyploid seeds comprising a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, and (b) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the second MiMe component, wherein the population was obtained from a single parent plant or a set of plants, such as a set of F1 hybrids. The polyploid seeds (e.g., the subpopulation of genetically uniform seeds) can be, for example, triploid, tetraploid, pentaploid, hexaploid, hexaploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds is genetically homogeneous. In certain embodiments, the population of polyploid seeds has a mean pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient.In certain embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain embodiments, each pair of seeds in the subpopulation of genetically uniform polyploid seeds has a pairwise identity of at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient. In some embodiments, the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component.

[0028] In another aspect, the present disclosure provides a population of polyploid seeds having a partially complemented MiMe genotype including (a) only a MiMe allele at one or more MiMe loci of a first MiMe component (wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination), (b) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a second MiMe component, (c) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a third MiMe component, and (d) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, wherein at least 50% of the population of polyploid seeds is genetically homogeneous, and the population was obtained from a single parent plant or set of plants, such as, for example, a set of F1 hybrids. In some embodiments, the present disclosure provides a population of polyploid seeds comprising a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise a partially complemented MiMe genotype comprising: (a) only MiMe alleles at one or more MiMe loci of a first MiMe component (wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination); (b) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a second MiMe component; (c) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a third MiMe component; and (d) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, wherein the population was obtained from a single parent plant or set of plants, such as a set of F1 hybrids. Polyploid seeds (e.g., a subpopulation of genetically uniform seeds) can be, for example, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds is genetically uniform.In certain embodiments, the population of polyploid seeds has an average pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity index. In certain embodiments, the population of polyploid seeds comprises a subpopulation of genetically homogeneous polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain embodiments, each pair of seeds in the subpopulation of genetically homogeneous polyploid seeds has a pairwise identity of at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity index. In some embodiments, the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (3) a component of progression during the second division of meiosis, and (4) a component of progression during the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component are different MiMe components.

[0029] In some embodiments of the foregoing aspects, the first MiMe component is a component of sister chromatid cohesion during meiosis I. In some variations, one or more MiMe loci of the first MiMe component comprise REC8, SWITCH1 / DYAD, or a combination thereof. In one variation, the MiMe locus of the first MiMe component is REC8. In certain embodiments, the second MiMe component is a component of DNA double-strand breaks during meiotic recombination. In some variations, the first MiMe locus and the second MiMe locus of the second MiMe component comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In one variation, the first MiMe locus of the second MiMe component is PAIR1 and the second MiMe locus of the second MiMe component is SPO11-1. In a further embodiment, the third MiMe component is a component of progression during the second division of meiosis. In some embodiments, the partially complemented MiMe genotype comprises only MiMe alleles at one or more MiMe loci of the third MiMe component. In some variations, the one or more MiMe loci of the third MiMe component comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In one variation, the MiMe locus of the third MiMe component is OSD1. In other embodiments, the partially complemented MiMe genotype comprises one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of the third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the third MiMe component. In some variations, the first MiMe locus and the second MiMe locus of the third MiMe component comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.In one embodiment, the partially complemented MiMe genotype comprises only MiMe alleles at one or more MiMe loci of a third MiMe component, wherein the one or more MiMe loci having only MiMe alleles of the first MiMe component comprise REC8, the first MiMe locus of the second MiMe component is PAIR1, the second MiMe locus of the second MiMe component is SPO11-1, and the one or more MiMe loci having only MiMe alleles of the third MiMe component comprise OSD1. In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in altered activity of one or more, two or more, or three or more MiMe components. In some embodiments, altered activity includes, for example, dominant-negative mutants, constitutively active mutants, or null mutants of one or more MiMe components.

[0030] In some embodiments of the foregoing aspects, the population of polyploid seeds or the subpopulation of genetically uniform polyploid seeds comprises: (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more sole MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1.

[0031] In some embodiments of the foregoing aspects, the population of polyploid seeds or the subpopulation of genetically uniform polyploid seeds comprises: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1), and (iv) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0032] In some embodiments of the foregoing aspects, the population of polyploid seeds or the subpopulation of genetically uniform polyploid seeds comprises: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; (iii) only MiMe alleles at one or more PAIR1 loci. and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1, and (iv) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1.

[0033] In some embodiments of the foregoing aspects, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partially complemented MiMe genotype that includes (i) a ps allele (wherein the subpopulation of genetically uniform polyploid seeds is heterozygous for the ps allele), (ii) an os allele (wherein the subpopulation of genetically uniform polyploid seeds is heterozygous for the os allele), (iii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iv) only a MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0034] In some embodiments of the foregoing aspects, the population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds has a partially complemented MiMe genotype that includes (i) an os allele (wherein the subpopulation of genetically uniform polyploid seeds is heterozygous for the os allele), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (iii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iv) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0035] In another aspect, the present disclosure provides methods for producing a population of polyploid seeds described herein, the method comprising: (a) providing clonal gametes from a pair of MiMe parent plants that collectively contain three or more haplotypes; and (b) crossing the clonal gametes to produce the population of polyploid seeds. In some embodiments, at least 50% of the population of polyploid seeds are genetically uniform and contain three or more haplotypes. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds produced by the method are genetically uniform. In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform seeds in an amount of at least 50% of the total number of seeds, the subpopulation of genetically uniform seeds comprising three or more haplotypes. In certain embodiments, the polyploid seed population comprises a genetically uniform subpopulation of seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain embodiments, the polyploid seeds (e.g., a genetically uniform subpopulation of polyploid seeds) produced by the method comprise four or more haplotypes of plants of the same or closely related species. The polyploid seed population or genetically uniform subpopulation of polyploid seeds can be, for example, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In some embodiments, germination of seeds from the polyploid seed population (e.g., a genetically uniform subpopulation of polyploid seeds) produced by the method results in sterile plants that produce nonviable gametes, seedless fruit, or a combination thereof.The method may be used to grow a variety of fruits, including, but not limited to, potatoes, corn, bananas, blueberries, blackberries, watermelons, cantaloupes, tomatoes, tomatillos, peppers, eggplants, grapes, oranges, lemons, limes, grapefruits, cucumbers, squash, gourds, pumpkins, apples, pears, kiwis, pomegranates, mangoes, guavas, papayas, avocados, stone fruits, dates, figs, alfalfa, tobacco, cotton, clover, strawberries, currants, cranberries, gooseberries, boysenberries, raspberries, and ar Tichokes, beets, potatoes, sweet potatoes, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yams, radishes, horseradish, turnips, parsnips, rutabaga, yucca, corn, onions, shallots, leeks, radishes, garlic, chives, peanuts, asparagus, sugarcane, cassava, Brussels sprouts, cabbage, collard greens, kale, lettuce, Swiss chard, spinach, pak choy, okra, cashews, pineapple, and celeriac. oats, birch, rapeseed, mustard, tea, hemp, safflower seeds, cedar, quinoa, chickpeas, citron, satsuma mandarins, tangerines and mandarins, clementines, coffee, cola tree, hazelnuts, saffron, melons and cantaloupes, carrots, oil palm, teff, rubber rabbitbrush, eucalyptus, fir, soybeans, sunflowers, hemlock trees, rubber trees, kenaf, barley, hops, walnuts, larch, lentils, flax, ryegrass, maple, silver grass, basil, olives, rice, millet, goumba It can be used to produce populations of polyploid seeds that can be from any plant species, including lightning purse, green beans, kidney beans, ground cherries, pine, pistachio nuts, peas, turfgrass, poplar, apricots, plums and prunes, almonds, nectarines, peaches, cherries, roses, bramble, rye, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, wheat, broad beans, cowpeas, ginger, kohlrabi, broccoli, and cauliflower.

[0036] Some embodiments of the method for producing a population of polyploid seeds include producing a population of polyploid seeds comprising one or more genetic modifications that result in reduced expression of one or more, two or more, or three or more MiMe loci. The population of polyploid seeds or a subpopulation of genetically uniform polyploid seeds may comprise one or more genetic modifications that result in reduced expression of MiMe loci, including, but not limited to, REC8, OSD1, CYCA1, TDM1, PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, JASON, PC1, PC2, and FC. In one embodiment, the polyploid seeds or subpopulation of genetically uniform polyploid seeds produced by the method comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In another embodiment, the polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above methods comprise one or more genetic modifications that result in reduced expression of OSD1, CYCA1, TDM1, PC1, PC2, FC, or a combination thereof. In another embodiment, the polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above methods comprise one or more genetic modifications that result in reduced expression of PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or a combination thereof. In yet another embodiment, the polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above methods comprise one or more genetic modifications that result in reduced expression of PS1, JASON, or a combination thereof. The polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above methods may comprise genetic modifications at any combination of the MiMe loci described herein.Genetic modifications may include, but are not limited to, modifications of enhancers at the MiMe locus, modifications of promoters at the MiMe locus, modifications of coding regions at the MiMe locus, modifications of the methylation status of the MiMe locus, expression of repressor proteins that target DNA or mRNA at the MiMe locus, and expression of RNA interference constructs that target mRNA from the MiMe locus.

[0037] In certain embodiments, the population of polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above method comprises a complete MiMe genotype comprising MiMe alleles that confer reduced expression of one or more MiMe loci for each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In other embodiments, the population of polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above method comprises a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first, second, and third MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations, the one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof.In yet an additional variation, one or more MiMe loci of a component of progression through meiotic division II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0038] In certain embodiments, the population of polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above method has a complete MiMe genotype including MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component. In other embodiments, the population of polyploid seeds, or a subpopulation of genetically uniform polyploid seeds, produced by the above method has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations, the one or more MiMe loci of a component of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations, the one or more MiMe loci of a component of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0039] In another aspect, the disclosure provides a method for producing a population of polyploid seeds described herein having a partially complemented MiMe genotype, comprising: (a) providing clonal gametes from a first MiMe parent plant, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, only non-MiMe alleles at a second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of a third MiMe component; (b) providing clonal gametes from the second MiMe parent plant; (c) providing clonal gametes from the first and second MiMe parent plants, wherein the second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, only MiMe alleles at the second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of the third MiMe component; and (c) crossing clonal gametes from the first and second MiMe parent plants to produce a population of polyploid seeds having partially complemented MiMe genotypes. In some embodiments, at least 50% of the population of polyploid seeds is genetically homogeneous and comprises two, three, or more haplotypes. In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform seeds in an amount of at least 50% of the total number of seeds, the subpopulation of genetically uniform seeds comprising a partially complemented MiMe genotype. In certain embodiments, at least one MiMe locus of a first MiMe parent plant that has only MiMe alleles of a first MiMe component is the same as at least one MiMe locus of a second MiMe parent plant that has only MiMe alleles of a first MiMe component.In some embodiments, at least one MiMe locus of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one MiMe locus of the second MiMe parent plant that has only a MiMe allele of the third MiMe component. In other embodiments, one or more MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from one or more MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component. In some embodiments, the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during meiotic division I, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through meiotic division II, and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components.

[0040] In another aspect, the disclosure provides a method for producing a population of polyploid seeds having a partially complemented MiMe genotype as described herein, comprising: (a) providing clonal gametes from a first MiMe parent plant, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; (b) providing clonal gametes from a second MiMe parent plant; The method includes (c) providing clonal gametes from a second MiMe parent plant having only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, and only MiMe alleles at the second MiMe locus of the second MiMe component; and (c) crossing clonal gametes from the first and second MiMe parent plants to produce a population of polyploid seeds having a partially complemented MiMe genotype. In some embodiments, at least 50% of the population of polyploid seeds are genetically uniform and comprise two, three, or more haplotypes. In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform seeds in an amount of at least 50% of the total number of seeds, the subpopulation of genetically uniform seeds comprising a partially complemented MiMe genotype. In some embodiments, at least one MiMe locus of the first MiMe parent plant that has only a MiMe allele of the first MiMe component is the same as at least one MiMe locus of the second MiMe parent plant that has only a MiMe allele of the first MiMe component. In certain embodiments, the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component.

[0041] In yet another aspect, the present disclosure provides a method for producing a population of polyploid seeds having a partially complemented MiMe genotype as described herein, comprising: (a) providing clonal gametes from a first MiMe parent plant, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at one or more MiMe loci of a second MiMe component, only MiMe alleles at one or more MiMe loci of a third MiMe component, and only non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, the first MiMe component being a component of a DNA double-strand break during meiotic recombination; (b) providing clonal gametes from a second MiMe parent plant, the second MiMe parent plant having only MiMe alleles at the one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the one or more MiMe loci of the second MiMe component, only non-MiMe alleles at the one or more MiMe loci of the third MiMe component, and only MiMe alleles at the one or more MiMe loci of the fourth MiMe component, and (c) crossing the clonal gametes from the first and second MiMe parent plants to produce a population of polyploid seeds having partially complemented MiMe genotypes. In some embodiments, at least 50% of the population of polyploid seeds is genetically homogeneous and comprises two, three, or more haplotypes. In some embodiments, the population of polyploid seeds comprises a genetically uniform subpopulation of seeds in an amount of at least 50% of the total number of seeds, the genetically uniform subpopulation of seeds comprising a partially complemented MiMe genotype, and in some embodiments, at least one MiMe locus of a first MiMe parent plant that has only MiMe alleles of a first MiMe component is the same as at least one MiMe locus of a second MiMe parent plant that has only MiMe alleles of a first MiMe component.In certain embodiments, the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (3) a component of progression during the second division of meiosis, and (4) a component of progression during the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component are different MiMe components.

[0042] In some embodiments of the aforementioned methods, the first MiMe component is a component of sister chromatid cohesion during the first division of meiosis. In some variations of the above methods, the MiMe loci of the first MiMe components of both the first and second MiMe parent plants comprise REC8. In certain embodiments of the above methods, the second MiMe component is a component of DNA double-strand breaks during meiotic recombination. In some variations of the above methods, the first MiMe locus and the second MiMe locus of the second MiMe component comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In one variation of the above method, the first MiMe locus of the second MiMe component is PAIR1 and the second MiMe locus of the second MiMe component is SPO11-1. In further embodiments of the above method, the third MiMe component is a component of progression through the second division of meiosis. In some embodiments of the above method, at least one MiMe locus of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one MiMe locus of the second MiMe parent plant that has only a MiMe allele of the third MiMe component. In some variations, the MiMe loci that have only a MiMe allele of a component of progression through the second division of meiosis include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In one variation, the MiMe locus that has only a MiMe allele of the third MiMe component is OSD1. In other embodiments of the above method, the one or more MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from the one or more MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component. In some variations, the MiMe loci having only MiMe alleles of the third MiMe component include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.In one variation of the above method, the MiMe locus having only MiMe alleles of the first MiMe component comprises REC8, the first MiMe locus of the second MiMe component is PAIR1, the second MiMe locus of the second MiMe component is SPO11-1, and the MiMe locus having only MiMe alleles of the third MiMe component comprises OSD1.

[0043] In another aspect, the present disclosure provides a method for breeding polyploid hybrid plant lines, comprising: (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate plant lines; (c) selecting two or more candidate lines that collectively contain three or more haplotypes; (d) generating two MiMe parent plants from the two or more candidate lines that collectively contain the three or more haplotypes; (e) providing clonal gametes from each of the MiMe parent plants; (f) crossing the clonal gametes to produce hybrid polyploid seeds that contain the three or more haplotypes; (g) cultivating the hybrid polyploid seeds to produce hybrid polyploid plants that contain three or more haplotypes; and (h) evaluating one or more characteristics of the hybrid polyploid plants. The candidate lines and MiMe parent plants can be of any ploidy, including, but not limited to, haploid, haploid, diploid, triploid, or tetraploid. In additional embodiments of the above breeding methods, the hybrid polyploid plant is tetraploid, pentaploid, hexaploid, 7ploid, or octaploid.

[0044] In some embodiments of the breeding method, step (d) comprises directly introducing a complete MiMe genotype into two candidate lines to produce two MiMe parent plants. In other embodiments of the breeding method, step (d) comprises introducing a partial MiMe genotype into two candidate lines to produce two non-MiMe grandparent plants, each having a partial MiMe genotype, crossing the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce a first MiMe parent plant, and directly introducing a complete MiMe genotype into a third candidate line to produce a second MiMe parent plant. In yet other embodiments of the breeding method, step (d) comprises introducing a partial MiMe genotype into four candidate lines to produce four non-MiMe grandparent plants, each having a partial MiMe genotype, and crossing a pair of the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce two MiMe parent plants. In certain embodiments, step (d) further comprises propagating the MiMe parent plant for large-scale production of homogenous seed.

[0045] In some embodiments of the above-described breeding method, each of the MiMe parent plants in step (d) has a complete MiMe genotype, including naturally occurring MiMe alleles, MiMe alleles introduced by genetic modification, or a combination thereof. In certain embodiments, the genetic modification results in reduced expression of one or more, two or more, or three or more MiMe loci, including, but not limited to, REC8, OSD1, CYCA1, TDM1, PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, JASON, PC1, PC2, and FC. In one embodiment, the genetic modification results in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In another embodiment, the genetic modification results in reduced expression of OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In another embodiment, the genetic modification results in reduced expression of PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet another embodiment, the genetic modification results in reduced expression of PS1, JASON, or any combination thereof. In some embodiments, one or more genetic modifications are introduced by gene editing, gene transfer, or a combination thereof. The genetic modification can be achieved by any method described herein, including, but not limited to, gene disruption, gene knockout, gene knockdown, gene silencing, RNA interference, induced methylation, or any combination thereof.

[0046] In certain embodiments, the population of polyploid seeds produced by the above breeding method comprises a complete MiMe genotype comprising MiMe alleles that confer reduced expression of one or more MiMe loci for each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In other embodiments, the population of polyploid seeds produced by the above breeding method comprises a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first, second, and third MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations, the one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet additional variations, the one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0047] In certain embodiments, the population of polyploid seeds produced by the above breeding method has a complete MiMe genotype including MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component. In other embodiments, the population of polyploid seeds produced by the above breeding method has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations, the one or more MiMe loci of a component of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations, the one or more MiMe loci of a component of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0048] In certain embodiments of the above breeding methods, the method of breeding a population of polyploid seeds further comprises (i) repeating steps (b)-(h) or steps (c)-(h) using one or more traits of the hybrid polyploid plants evaluated in step (h) to guide the breeding of lines in step (b), the selection of candidate lines in step (c), or both. In some variations, the one or more traits include heterosis performance of three or more haplotypes of the polyploid hybrid plants evaluated in step (h).

[0049] In some embodiments of the breeding method, the set of lines in step (a) is obtained by one or more of natural diversity, existing breeding programs, or dihaploid derivation of polyploid lines. In certain embodiments of the breeding method, step (a) further comprises organizing the set of lines into three or more heterosis groups, each heterosis group comprising haplotypes, the haplotypes being classified based on observed or predicted heterosis performance when combined into the hybrid polyploid plant of step (g). In one variation, step (a) comprises organizing the set of lines into four or more heterosis groups. In certain embodiments, heterosis performance is predicted by genomic predictive modeling. In some embodiments of the above-described breeding methods, step (b) comprises reciprocal recurrent selection, inbreeding with homozygosity of one or more of the plant lines, producing doubled haploid lines (e.g., doubled haploid lines), backcrossing, or any other method known in the art for producing plant lines with a high degree of homozygosity, or a combination thereof. The candidate lines for step (c) can be inbred lines, hybrid lines, or a combination thereof.

[0050] In another aspect, the present disclosure provides a method for producing a population of polyploid seeds, the method comprising: (a) providing clonal gametes from a pair of MiMe parent plants, collectively comprising three or more haplotypes selected using the breeding methods described herein, based on a polyploid plant comprising three or more haplotypes having one or more desired characteristics; and (b) crossing the clonal gametes to produce a population of polyploid seeds, wherein at least 50% of the population of polyploid seeds is genetically uniform and comprises three or more haplotypes. The polyploid seeds produced by the method can be, for example, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds produced by the method is genetically uniform. In certain embodiments, the polyploid seeds produced by the methods include four or more haplotypes of the same or closely related plant species. In some variations of the methods, the plant lineages are maintained by vegetative propagation, selfing, apomixis, cell culture, or any combination thereof. In some embodiments, the methods further include maintaining an inventory of plant lineages from which haplotypes can be selected for rapid definitive stacking of haplotypes. In some variations, the inventory of lineages includes one or more plant lineages with a complete MiMe genotype maintained by vegetative propagation, hybridization with haploid derivatives, or a combination thereof. In additional variations, the inventory of lineages includes one or more plant lineages with a partial MiMe genotype.

[0051] In another aspect, the present disclosure provides a method for producing a population of polyploid seeds, the method comprising: (a) providing clonal gametes from a MiMe parent plant; (b) providing haploid (e.g., haploid) gametes from a homozygous non-MiMe parent plant; and (c) crossing the clonal gametes with haploid (e.g., haploid) gametes to produce the population of polyploid seeds, wherein the clonal gametes and the haploid (e.g., haploid) gametes collectively comprise three or more haplotypes, and at least 50% of the population of polyploid seeds is genetically homogeneous and comprises three or more haplotypes. The MiMe parent plant can be, for example, diploid, triploid, or tetraploid. The homozygous non-MiMe parent plant can be, for example, diploid or tetraploid. The polyploid seeds produced by the method can be, for example, triploid, tetraploid, pentaploid, hexaploid, hexaploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds produced by the methods are genetically homogeneous. In certain embodiments, the polyploid seeds produced by the methods comprise four or more haplotypes of plants of the same or closely related species. In some embodiments, germination of seeds from the population of polyploid seeds produced by the methods results in sterile plants that produce nonviable gametes, seedless fruit, or a combination thereof.The method may be used to grow a variety of fruits, including, but not limited to, potatoes, corn, bananas, blueberries, blackberries, watermelons, cantaloupes, tomatoes, tomatillos, peppers, eggplants, grapes, oranges, lemons, limes, grapefruits, cucumbers, squash, gourds, pumpkins, apples, pears, kiwis, pomegranates, mangoes, guavas, papayas, avocados, stone fruits, dates, figs, alfalfa, tobacco, cotton, clover, strawberries, currants, cranberries, gooseberries, boysenberries, raspberries, and ar Tichokes, beets, potatoes, sweet potatoes, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yams, radishes, horseradish, turnips, parsnips, rutabaga, yucca, corn, onions, shallots, leeks, radishes, garlic, chives, peanuts, asparagus, sugarcane, cassava, Brussels sprouts, cabbage, collard greens, kale, lettuce, Swiss chard, spinach, pak choy, okra, cashews, pineapple, and celeriac. oats, birch, rapeseed, mustard, tea, hemp, safflower seeds, cedar, quinoa, chickpeas, citron, satsuma mandarins, tangerines and mandarins, clementines, coffee, cola tree, hazelnuts, saffron, melons and cantaloupes, carrots, oil palm, teff, rubber rabbitbrush, eucalyptus, fir, soybeans, sunflowers, hemlock trees, rubber trees, kenaf, barley, hops, walnuts, larch, lentils, flax, ryegrass, maple, silver grass, basil, olives, rice, millet, goumba It can be used to produce populations of polyploid seeds that can be from any plant species, including lightning purse, green beans, kidney beans, ground cherries, pine, pistachio nuts, peas, turfgrass, poplar, apricots, plums and prunes, almonds, nectarines, peaches, cherries, roses, bramble, rye, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, wheat, broad beans, cowpeas, ginger, kohlrabi, broccoli, and cauliflower.

[0052] In some embodiments, a method for producing a population of polyploid seeds includes producing a population of polyploid seeds comprising one or more genetic modifications that result in reduced expression of one or more, two or more, or three or more MiMe loci. The seeds may comprise one or more genetic modifications that result in reduced expression of MiMe loci, including, but not limited to, REC8, OSD1, CYCA1, TDM1, PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, JASON, PC1, PC2, and FC. In one embodiment, the polyploid seeds produced by the method comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In another embodiment, the polyploid seeds produced by the method comprise one or more genetic modifications that result in reduced expression of OSD1, CYCA1, TDM1, PC1, PC2, FC, or a combination thereof. In another embodiment, the polyploid seeds produced by the above method contain one or more genetic modifications that result in reduced expression of PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or a combination thereof. In yet another embodiment, the polyploid seeds produced by the above method contain one or more genetic modifications that result in reduced expression of PS1, JASON, or a combination thereof. The polyploid seeds produced by the above method may contain genetic modifications at any combination of the MiMe loci described herein. Genetic modifications may include, but are not limited to, modifications of enhancers at the MiMe loci, modifications of promoters at the MiMe loci, modifications of coding regions at the MiMe loci, modifications of the methylation status of the MiMe loci, expression of repressor proteins targeting DNA or mRNA at the MiMe locus, and expression of RNA interference constructs targeting mRNA from the MiMe locus.

[0053] In certain embodiments, the population of polyploid seeds produced by the above method comprises a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first, second, and third MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations, the one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet additional variations, the one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0054] In certain embodiments, the population of polyploid seeds produced by the above method has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations, the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In a further variation, one or more MiMe loci of a component of progression through meiosis I include PS1, JASON, or a combination thereof.

[0055] In another aspect, the disclosure provides a method for (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate lines of the plant; (c) selecting two or more candidate lines that collectively comprise three or more haplotypes; (d) generating a MiMe parent plant from one of the two or more candidate lines; (e) providing clonal gametes from the MiMe parent plant; (f) providing haploid (e.g., haploid) gametes from a homozygous non-MiMe parent plant of one of the two or more candidate lines; (g) cultivating the clonal gametes from the MiMe parent plant; (g) crossing the MiMe parent plant with the haploid (e.g., haploid) gamete to produce hybrid polyploid seed; (h) cultivating the hybrid polyploid seed to produce a hybrid polyploid plant; and (i) evaluating one or more characteristics of the hybrid polyploid plant, wherein the MiMe parent plant and the homozygous non-MiMe parent plant collectively comprise three or more haplotypes, the crossing in step (g) results in the hybrid polyploid seed comprising three or more haplotypes, and the cultivating in step (h) results in the hybrid polyploid plant comprising three or more haplotypes. The candidate line, MiMe parent plant, and homozygous non-MiMe parent plant can be of any ploidy, including, but not limited to, haploid, haploid, diploid, triploid, or tetraploid. In some embodiments of the above breeding methods, the hybrid polyploid plant is tetraploid, pentaploid, hexaploid, 7ploid, or octaploid.

[0056] In some embodiments of the breeding method, step (d) comprises directly introducing the complete MiMe genotype into the candidate line to produce a MiMe parent plant. In further embodiments of the breeding method, step (d) comprises introducing a partial MiMe genotype into two candidate lines to produce two non-MiMe grandparent plants, each having a partial MiMe genotype, and crossing the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce a MiMe parent plant. In certain embodiments, step (d) further comprises propagating the MiMe parent plants for large-scale production of homogenous seeds.

[0057] In some embodiments of the above-described breeding method, the MiMe parent plant in step (d) has a complete MiMe genotype, including naturally occurring MiMe alleles, MiMe alleles introduced by genetic modification, or a combination thereof. In certain embodiments, the genetic modification results in reduced expression of one or more, two or more, or three or more MiMe loci, including, but not limited to, REC8, OSD1, CYCA1, TDM1, PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, JASON, PC1, PC2, and FC. In one embodiment, the genetic modification results in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In another embodiment, the genetic modification results in reduced expression of OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In another embodiment, the genetic modification results in reduced expression of PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet another embodiment, the genetic modification results in reduced expression of PS1, JASON, or any combination thereof. In some embodiments, one or more genetic modifications are introduced by gene editing, gene transfer, or a combination thereof. The genetic modification can be achieved by any method described herein, including, but not limited to, gene disruption, gene knockout, gene knockdown, gene silencing, RNA interference, induced methylation, or any combination thereof.

[0058] In certain embodiments, the population of polyploid seeds produced by the above breeding method comprises a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first, second, and third MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations, the one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In additional variations, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet additional variations, the one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0059] In certain embodiments, the population of polyploid seeds produced by the above breeding method has a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations, the one or more MiMe loci of a component of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations, the one or more MiMe loci of a component of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0060] In certain embodiments of the above breeding methods, the method of breeding a population of polyploid seeds further includes (j) repeating steps (b)-(i) or steps (c)-(i) using one or more traits of the hybrid polyploid plants evaluated in step (i) to guide the breeding of lines in step (b), the selection of candidate lines in step (c), or both. In some variations, the one or more traits include heterosis performance of three or more haplotypes of the polyploid hybrid plants evaluated in step (i).

[0061] In some embodiments of the breeding method, the set of lines in step (a) is obtained by one or more of natural diversity, existing breeding programs, or dihaploid derivation of polyploid lines. In certain embodiments of the breeding method, step (a) further comprises organizing the set of lines into three or more heterosis groups, each heterosis group comprising haplotypes, the haplotypes being classified based on observed or predicted heterosis performance when combined into the hybrid polyploid plant of step (h). In one variation, step (a) comprises organizing the set of lines into four or more heterosis groups. In certain embodiments, heterosis performance is predicted by genomic predictive modeling. In some embodiments of the above-described breeding methods, step (b) comprises reciprocal recurrent selection, inbreeding with homozygosity of one or more of the plant lines, producing doubled haploid lines (e.g., doubled haploid lines), backcrossing, or any other method known in the art for producing plant lines with a high degree of homozygosity, or a combination thereof. The candidate lines for step (c) can be inbred lines, hybrid lines, or a combination thereof.

[0062] In another aspect, the disclosure provides a method of producing a population of polyploid seeds, the method comprising: (a) selecting three or more haplotypes having one or more desired characteristics based on a polyploid plant comprising three or more haplotypes using the breeding methods described herein; (b) providing clonal gametes from a MiMe parent plant; (c) providing haploid (e.g., haploid) gametes from a homozygous non-MiMe parent plant; and (d) crossing the clonal gametes with the haploid (e.g., haploid) gametes to produce the population of polyploid seeds, wherein the MiMe parent plant and the homozygous non-MiMe parent plant collectively comprise the three or more haplotypes selected in step (a), and the crossing in step (d) results in a population of polyploid seeds comprising the three or more haplotypes selected in step (a), and at least 50% of the population of polyploid seeds is genetically homogeneous and comprises the three or more haplotypes. The polyploid seeds produced by the methods can be, for example, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In some embodiments, at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds produced by the methods is genetically uniform. In certain embodiments, the polyploid seeds produced by the methods comprise four or more haplotypes of the same or closely related plants. In some variations of the methods, the plant lineage is maintained by vegetative propagation, selfing, apomixis, cell culture, or any combination thereof. In some embodiments, the method further includes maintaining an inventory of plant lineages from which haplotypes can be selected for rapid definitive stacking of haplotypes. In some variations, the inventory of lineages includes one or more plant lines with complete MiMe genotypes maintained by vegetative propagation, hybridization with haploid derivatives, or a combination thereof. In a further variation, the lineage inventory includes one or more plant lines with a partial MiMe genotype.

[0063] In another aspect, the disclosure provides a method for producing a plant using a method of culturing a plant, the method comprising: (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate plant lines; (c) selecting one or more candidate lines; (d) generating a first MiMe parent plant from one of the candidate lines, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, only non-MiMe alleles at a second MiMe locus of a second MiMe component, and only MiMe alleles at one or more MiMe loci of a third MiMe component; and (e) generating a second MiMe parent plant from one of the candidate lines, the second MiMe parent plant having only MiMe alleles at one or more MiMe loci of the first MiMe component. (f) producing polyploid plants having only non-MiMe alleles at the first MiMe locus of the second MiMe component, only MiMe alleles at the second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of the third MiMe component, wherein at least one of the MiMe loci of the first MiMe component having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe component having only MiMe alleles of the first MiMe component; (f) providing clonal gametes from each of the MiMe parent plants; (g) crossing the clonal gametes to produce polyploid seeds; (h) cultivating the polyploid seeds to produce polyploid plants; and (i) evaluating one or more characteristics of the polyploid plants. In some embodiments, at least one of the MiMe loci of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only a MiMe allele of the third MiMe component.In other embodiments, one or more MiMe loci in the first MiMe parent plant that have only MiMe alleles of the third MiMe component are different from one or more MiMe loci in the second MiMe parent plant that have only MiMe alleles of the third MiMe component. In certain embodiments, the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during meiotic division I, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through meiotic division II, and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components.

[0064] In some embodiments of the breeding methods, the first MiMe component is a component of sister chromatid cohesion during meiosis I. In some variations of the breeding methods, the MiMe loci of the first MiMe components of both the first and second MiMe parent plants comprise REC8. In certain embodiments of the breeding methods, the second MiMe component is a component of DNA double-strand breaks during meiotic recombination. In some variations of the breeding methods, the first MiMe locus and the second MiMe locus of the second MiMe component comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In one variation of the breeding method, the first MiMe locus of the second MiMe component is PAIR1 and the second MiMe locus of the second MiMe component is SPO11-1. In further embodiments of the breeding method, the third MiMe component is a component of progression through the second division of meiosis. In some embodiments of the breeding method, at least one MiMe locus of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one MiMe locus of the second MiMe parent plant that has only a MiMe allele of the third MiMe component. In some variations, the MiMe loci that have only a MiMe allele of a component of progression through the second division of meiosis include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In one variation, the MiMe locus that has only a MiMe allele of the third MiMe component is OSD1. In other embodiments of the breeding method, the one or more MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from the one or more MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component. In some variations, the MiMe loci having only MiMe alleles of the third MiMe component include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.In one variation of the above breeding method, the MiMe locus having only MiMe alleles of the first MiMe component comprises REC8, the first MiMe locus of the second MiMe component is PAIR1, the second MiMe locus of the second MiMe component is SPO11-1, and one or more MiMe loci having only MiMe alleles of the third MiMe component comprise OSD1.

[0065] In another aspect, the disclosure provides a method for producing a population of polyploid seeds, comprising: (a) providing clonal gametes from a pair of MiMe parent plants that collectively comprise two or more haplotypes having one or more desired characteristics, selected using the breeding method described above, based on a polyploid plant that comprises two or more haplotypes, wherein (i) a first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, only non-MiMe alleles at a second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of a third MiMe component; and (ii) a second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component. (iii) at least one of the MiMe loci of the first MiMe parent plant having only a non-MiMe allele at the first MiMe locus of the second MiMe component, only a MiMe allele at the second MiMe locus of the second MiMe component, and only a MiMe allele at one or more MiMe loci of the third MiMe component, is identical to at least one of the MiMe loci of the second MiMe parent plant having only a MiMe allele of the first MiMe component; and (b) crossing the clonal gametes to produce a population of polyploid seeds, wherein at least 50% of the population of polyploid seeds is genetically homogeneous and comprises two or more haplotypes. In some embodiments, at least one of the MiMe loci of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only a MiMe allele of the third MiMe component, hi other embodiments, one or more of the MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from one or more of the MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component.

[0066] In another aspect, the disclosure provides a method for producing a plant using a method of cultivating a plant, the method comprising: (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate plant lines; (c) selecting one or more candidate lines; (d) generating a first MiMe parent plant from one of the candidate lines, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; and (e) generating a second MiMe parent plant from one of the candidate lines, the second MiMe parent plant having only MiMe alleles at one or more MiMe loci of the first MiMe component. (f) producing polyploid plants having only a MiMe allele at the first MiMe locus of the second MiMe component, only a non-MiMe allele at the first MiMe locus of the second MiMe component, and only a MiMe allele at the second MiMe locus of the second MiMe component, wherein at least one of the MiMe loci having only a MiMe allele of the first MiMe component of the first MiMe component of the first MiMe parent plant is identical to at least one of the MiMe loci having only a MiMe allele of the first MiMe component of the second MiMe parent plant; (f) providing clonal gametes from each of the MiMe parent plants; (g) crossing the clonal gametes to produce polyploid seeds; (h) cultivating the polyploid seeds to produce polyploid plants; and (i) evaluating one or more characteristics of the polyploid plants. In some embodiments of the above breeding method, the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component.

[0067] In another aspect, the disclosure provides a method for producing a population of polyploid seeds, comprising: (a) providing clonal gametes from a pair of MiMe parent plants that collectively comprise two or more haplotypes having one or more desired characteristics, selected using the breeding method described above, based on a polyploid plant that comprises two or more haplotypes, wherein (i) a first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; and (ii) a second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component. and (b) providing a polyploid seed population comprising at least one MiMe locus of the second MiMe component, the first MiMe parent plant having only non-MiMe alleles at the first MiMe locus of the second MiMe component and only MiMe alleles at the second MiMe locus of the second MiMe component, and (iii) at least one MiMe locus of the first MiMe component having only MiMe alleles of the first MiMe component is identical to at least one MiMe locus of the second MiMe parent plant having only MiMe alleles of the first MiMe component; and (b) crossing the clonal gametes to produce a polyploid seed population, wherein at least 50% of the polyploid seed population is genetically homogeneous and comprises two or more haplotypes.

[0068] In another aspect, the disclosure provides a method for producing a plant from a first MiMe parent plant, the first MiMe parent plant having only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at one or more MiMe loci of a second MiMe component, only MiMe alleles at one or more MiMe loci of a third MiMe component, and only non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination; and (e) producing a second MiMe parent plant from one of the candidate lines, the second MiMe parent plant having only MiMe alleles at one or more MiMe loci of the first MiMe component. (f) providing clonal gametes from each of the MiMe parent plants; (g) crossing the clonal gametes to produce polyploid seeds; (h) cultivating the polyploid seeds to produce polyploid plants; and (i) evaluating one or more characteristics of the polyploid plants.In some embodiments of the above breeding method, the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of (1) components of sister chromatid cohesion during the first division of meiosis, (3) components of progression through the second division of meiosis, and (4) components of progression through the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component.

[0069] In another aspect, the disclosure provides a method for producing a population of polyploid seeds, comprising: (a) providing clonal gametes from a pair of MiMe parent plants that collectively comprise two or more haplotypes having one or more desired characteristics, selected using the breeding method described above, based on a polyploid plant that comprises two or more haplotypes, wherein (i) a first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; and (ii) a second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component. and (b) providing a polyploid seed population comprising at least one MiMe locus of the second MiMe component, the first MiMe parent plant having only non-MiMe alleles at the first MiMe locus of the second MiMe component and only MiMe alleles at the second MiMe locus of the second MiMe component, and (iii) at least one MiMe locus of the first MiMe component having only MiMe alleles of the first MiMe component is identical to at least one MiMe locus of the second MiMe parent plant having only MiMe alleles of the first MiMe component; and (b) crossing the clonal gametes to produce a polyploid seed population, wherein at least 50% of the polyploid seed population is genetically homogeneous and comprises two or more haplotypes.

[0070] In some embodiments of the aforementioned breeding methods, steps (d) and (e) comprise directly introducing a complete MiMe genotype into two candidate lines to produce two MiMe parent plants. In further embodiments of the aforementioned breeding methods, steps (d) and (e) comprise introducing a partial MiMe genotype into two candidate lines to produce two non-MiMe grandparent plants, each having a partial MiMe genotype, crossing the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce a first MiMe parent plant, and directly introducing a complete MiMe genotype into a third candidate line to produce a second MiMe parent plant. In still other embodiments of the aforementioned breeding methods, steps (d) and (e) comprise introducing a partial MiMe genotype into four candidate lines to produce four non-MiMe grandparent plants, each having a partial MiMe genotype, and crossing a pair of the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce two MiMe parent plants. In certain embodiments of the aforementioned breeding methods, steps (d) and (e) further comprise propagating the MiMe parent plants for large-scale production of homogenous seeds.

[0071] In some embodiments of the aforementioned breeding methods, the method further comprises (j) repeating steps (b)-(i) or steps (c)-(i) using one or more traits of the polyploid plants evaluated in step (i) to guide the breeding of the lines in step (b), the selection of candidate lines in step (c), or both. In certain embodiments of the aforementioned breeding methods, the one or more traits comprise the hybrid vigor performance of two, three, four, or more haplotypes of the polyploid plants evaluated in step (i). In some embodiments of the aforementioned breeding methods, the set of lines in step (a) is obtained by one or more of natural diversity, an existing breeding program, or dihaploid derivation of polyploid lines. In certain embodiments of the aforementioned breeding methods, step (a) further comprises organizing the set of lines into two, three, four, or more heterosis groups, each comprising haplotypes, the haplotypes being classified based on observed or predicted heterosis performance when combined into the polyploid plant of step (i). In some variations, heterosis performance is predicted by genomic predictive modeling. In some embodiments of the aforementioned breeding methods, step (b) comprises reciprocal recurrent selection, inbreeding to homozygosity of one or more of the plant lines, production of doubled haploid lines (e.g., doubled haploid lines), backcrossing, or any other method known in the art for generating plant lines with a high degree of homozygosity, or a combination thereof. In some embodiments of the aforementioned breeding methods, one or more of the candidate lines of step (c) are inbred lines. In further embodiments of the aforementioned breeding methods, one or more of the candidate lines of step (c) are hybrid lines.

[0072] In some embodiments of any of the above-described breeding methods, the first and second MiMe parent plants collectively comprise two, three, four, or more haplotypes, resulting in a polyploid plant comprising two, three, four, or more haplotypes. In some embodiments of the foregoing breeding methods, the plant lineage is maintained by vegetative propagation, selfing, apomixis, cell culture, or any combination thereof. In further embodiments of the above-described methods, the method further comprises maintaining an inventory of plant lines from which haplotypes can be selected for rapid definitive stacking of haplotypes. In some variations, the inventory of lines comprises one or more plant lines with a complete MiMe genotype maintained by vegetative propagation, hybridization with a haploid derivative, or a combination thereof. In an additional variation, the inventory of lines comprises one or more plant lines with a partial MiMe genotype.

[0073] In some embodiments of the above aspects and embodiments, one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In some embodiments of the above aspects and embodiments, one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In some embodiments of the above aspects and embodiments, one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In some embodiments of the above aspects and embodiments, one or more MiMe loci for components of progression through meiosis I include PS1, JASON, or a combination thereof.

[0074] In some embodiments of any of the above aspects and embodiments, the MiMe allele comprises a naturally occurring allele, an allele introduced by genetic modification, or a combination thereof. In certain embodiments of the above aspects and embodiments, the MiMe allele comprises one or more genetic modifications. In further embodiments of the above aspects and embodiments, one or more of the genetic modifications are present in a MiMe locus that encodes a gene product of the MiMe component. In some variations, the genetic modifications include modification of an enhancer at the MiMe locus, modification of a promoter at the MiMe locus, modification of a coding region at the MiMe locus, modification of the methylation status of the MiMe locus, expression of a repressor protein that targets DNA or mRNA at the MiMe locus, expression of an RNA interference construct that targets mRNA from the MiMe locus, or any combination thereof. In some embodiments of the above aspects and embodiments, the one or more genetic modifications are introduced by gene editing, gene transfer, or a combination thereof. In further embodiments of the above aspects and embodiments, the reduction of expression of one or more MiMe loci is achieved by gene disruption, gene knockout, gene knockdown, gene silencing, RNA interference, induced methylation, or any combination thereof.

[0075] In any of the above aspects and embodiments, the population of polyploid seeds can be, for example, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In some of the above aspects and embodiments, at least 50%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the population of polyploid seeds is genetically homogeneous. In some of the above aspects and embodiments, the population of polyploid seeds comprises a subpopulation of genetically homogeneous polyploid seeds in an amount of at least 50%, at least 70%, at least 75%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds. In certain of the above aspects and embodiments, the polyploid seeds (e.g., a genetically uniform subpopulation of polyploid seeds) comprise two, three, four, or more haplotypes of plants of the same or closely related species. In some of the above aspects and embodiments, germination of the seeds of the polyploid seed population or the genetically uniform subpopulation of polyploid seeds results in plants that produce inviable gametes, seedless fruit, or a combination thereof. In some embodiments, germination of the seeds of the polyploid seed population or the genetically uniform subpopulation of polyploid seeds results in seedless plants. In certain of the above aspects and embodiments, the polyploid seeds are from parthenocarpic plants.In any of the foregoing aspects and embodiments, the population of polyploid seeds may be selected from, but is not limited to, potato, corn, banana, blueberry, blackberry, watermelon, cantaloupe, tomato, tomatillo, pepper, eggplant, grapes, orange, lemon, lime, grapefruit, cucumber, squash, gourd, pumpkin, apple, pear, kiwi, pomegranate, mango, guava, papaya, avocado, stone fruit, date, fig, alfalfa, tobacco, cotton, clover, strawberry, currant, cranberry, gooseberry, boysenberry, raspberry, artichoke, beet, potato, sweet potato, edible canna, ajipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yam, radish, horseradish, turnip, parsnip, rutabaga Garlic, yucca, corn, onion, shallot, leek, radish, garlic, chives, peanuts, asparagus, sugarcane, cassava, Brussels sprouts, cabbage, collard greens, kale, lettuce, Swiss chard, spinach, bok choy, basil, okra, fir, maple, apricot, plantain, birch, cedar, cherry, citron, clementine, eucalyptus, nightshade, hops, ke It may be from any plant species, including knap, larch, melon and cantaloupe, miscanthus, nectarine, olive, switchgrass, peach, spruce, pine, pineapple, plum and prune, poplar, rubber rabbitbrush, rubber tree, Russian dandelion, satsuma mandarin, sorghum, tangerine and mandarin, teff, hemlock tree, turfgrass, kohlrabi, broccoli, and cauliflower.

[0076] In another aspect, the disclosure provides a genetically modified plant, plant part, or plant cell. In some embodiments, the genetically modified plant, plant part, or plant cell comprises a complete MiMe genotype comprising i) three or more haplotypes, and ii) MiMe alleles that confer reduced expression of one or more MiMe loci for each of a first, second, and third MiMe component, wherein the first, second, and third MiMe components are selected from the group consisting of: (1) a component of sister chromatid cohesion during meiotic division I, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through meiotic division II, and each of the first, second, and third MiMe components is a different MiMe component. In other embodiments, the genetically modified plant, plant part, or plant cell comprises i) three or more haplotypes, and ii) a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first, second, and third MiMe component, and (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first, second, and third MiMe components, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some variations of the above-described embodiments, one or more MiMe loci of components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof.In further variations of the above-described embodiments, the one or more MiMe loci of a component of DNA double-strand breaks during meiotic recombination comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In yet further variations of the above-described embodiments, the one or more MiMe loci of a component of progression through the second division of meiosis comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.

[0077] In some embodiments of the above-described genetically modified plant, plant part, or plant cell, the present disclosure provides a genetically modified plant, plant part, or plant cell comprising a complete MiMe genotype comprising i) three or more haplotypes, and ii) MiMe alleles that confer reduced expression of one or more MiMe loci for each of first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In other embodiments of this aspect, the genetically modified plant, plant part, or plant cell comprises i) three or more haplotypes, and ii) a partial MiMe genotype comprising (a) one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of the first and second MiMe components, and (b) one or more non-MiMe alleles at one or more MiMe loci of each of the first and second MiMe components, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations of the above-described embodiments, one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations of the above-described embodiments, one or more MiMe loci of components of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0078] In some embodiments of the genetically modified plant, plant part, or plant cell, the genetically modified plant, plant part, or plant cell comprises (i) at least first and second haplotypes comprising one or more MiMe alleles, each conferring reduced expression of one or more MiMe loci of each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are (1) components of sister chromatid cohesion during meiotic division I, (2) components of DNA double-strand breaks during meiotic recombination. and (3) a component of progression during meiosis II, wherein each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component, and (ii) at least a third haplotype comprising (a) a MiMe allele that confers decreased expression of a MiMe locus of a component of progression during meiosis I, or (b) a MiMe allele that confers decreased expression of a MiMe locus of a component of progression during meiosis II. In some variations of the above-described embodiments, the one or more MiMe loci of a component of sister chromatid cohesion during meiosis I comprise REC8, SWITCH1 / DYAD, or a combination thereof. In further variations of the above-described embodiments, the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In still further variations of the above-described embodiments, the MiMe locus of components of progression through the first meiotic division of the third haplotype is PS1 or JASON. In still further variations of the above-described embodiments, the one or more MiMe loci of components of progression through the second meiotic division of the first and second haplotypes comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof.In still further variations of the above embodiments, the component locus of progression through meiosis II of the third haplotype is OSD1, CYCA1, TDM1, PC1, PC2, or FC.

[0079] In some embodiments of the genetically modified plant, plant part, or plant cell, the genetically modified plant, plant part, or plant cell comprises: (i) at least first and second haplotypes, each comprising one or more MiMe alleles that confer reduced expression of one or more MiMe loci of each of a first and second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) a component of DNA double-strand breaks during meiotic recombination, and (4) a component of progression through the first division of meiosis, and wherein each of the first MiMe component and the second MiMe component are different MiMe components; and (ii) at least a third haplotype comprising a MiMe allele that conferred (a) reduced expression of a MiMe locus of a component of progression through the first division of meiosis, or (b) reduced expression of a MiMe locus of a component of progression through the second division of meiosis. In some variations of the above-described embodiments, one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In further variations of the above-described embodiments, one or more MiMe loci of components of progression through meiosis I of the first and second haplotypes include PS1, JASON, or a combination thereof. In still further variations of the above-described embodiments, the MiMe locus of components of progression through meiosis I of the third haplotype is PS1 or JASON. In still further variations of the above-described embodiments, the MiMe locus of components of progression through meiosis II of the third haplotype is OSD1, CYCA1, TDM1, PC1, PC2, or FC.

[0080] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0081] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci (wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0082] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0083] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1), (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0084] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0085] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) only MiMe alleles at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci (wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1).

[0086] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype including (i) an os allele (wherein the genetically modified plant, plant part, or plant cell is homozygous for the os allele), (ii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes: (i) an os allele (wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0087] In some embodiments, the genetically modified plant, plant part, or plant cell has a complete MiMe genotype that includes (i) a ps allele (wherein the genetically modified plant, plant part, or plant cell is homozygous for the ps allele) and (ii) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci contains one or more genetic modifications that result in reduced expression of SPO11-1). In some embodiments, the genetically modified plant, plant part, or plant cell has a partial MiMe genotype that includes (i) a ps allele (wherein the genetically modified plant, plant part, or plant cell is heterozygous for the ps allele), and (ii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci includes one or more genetic modifications that result in reduced expression of SPO11-1).

[0088] In some aspects, provided herein are genetically modified plants, plant parts, or plant cells having a partially complemented MiMe genotype. In some embodiments, the genetically modified plants, plant parts, or plant cells have (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, (b) one or more MiMe alleles and one or more non-MiMe alleles at the first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at the second MiMe locus of the second MiMe component, and (c) (i) only MiMe alleles at one or more MiMe loci of a third MiMe component, or (ii) one or more MiMe alleles and one or more non-MiMe alleles at the first MiMe locus of the third MiMe component. and a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during meiosis I, (2) a component of DNA double-strand breaks during meiotic recombination, and (3) a component of progression through meiosis II, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component. In some embodiments, the first MiMe component is a component of sister chromatid cohesion during meiosis I. In some variations, the one or more MiMe loci of the first MiMe component comprise REC8, SWITCH1 / DYAD, or a combination thereof. In one variation, the MiMe locus of the first MiMe component is REC8. In certain embodiments, the second MiMe component is a component of DNA double-strand breaks during meiotic recombination.In some variations, the first MiMe locus and the second MiMe locus of the second MiMe component comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In one variation, the first MiMe locus of the second MiMe component is PAIR1, and the second MiMe locus of the second MiMe component is SPO11-1. In further embodiments, the third MiMe component is a component of progression during meiosis II. In some embodiments, the partially complemented MiMe genotype comprises only MiMe alleles at one or more MiMe loci of the third MiMe component. In some variations, the one or more MiMe loci of the third MiMe component comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In one variation, the MiMe locus of the third MiMe component is OSD1. In other embodiments, the partially complemented MiMe genotype comprises one or more MiMe alleles and one or more non-MiMe alleles at the first MiMe locus of the third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at the second MiMe locus of the third MiMe component. In some variations, the first MiMe locus and the second MiMe locus of the third MiMe component comprise OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In one embodiment, the partially complemented MiMe genotype comprises only MiMe alleles at one or more MiMe loci of a third MiMe component, wherein the one or more MiMe loci having only MiMe alleles of a first MiMe component comprise REC8, the first MiMe locus of the second MiMe component is PAIR1, the second MiMe locus of the second MiMe component is SPO11-1, and the one or more MiMe loci having only MiMe alleles of a third MiMe component comprise OSD1.

[0089] In some embodiments, the present disclosure provides a genetically modified plant, plant part, or plant cell having a partially complemented MiMe genotype comprising (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. In some variations of the above-described embodiments, one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In additional variations of the above-described embodiments, one or more MiMe loci of components of progression through the first division of meiosis include PS1, JASON, or any combination thereof.

[0090] In some embodiments, the present disclosure provides a method for identifying a MiMe component comprising: (a) only a MiMe allele at one or more MiMe loci of a first MiMe component (wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination); (b) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a second MiMe component; (c) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a third MiMe component; and (d) one or more MiMe alleles at one or more MiMe loci of a fourth MiMe component. The present invention provides a genetically modified plant, plant part, or plant cell having a partially complemented MiMe genotype comprising a MiMe allele and one or more non-MiMe alleles, wherein the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of (1) a component of sister chromatid cohesion during meiosis I, (3) a component of progression through meiosis II, and (4) a component of progression through meiosis I, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component. In some variations of the above-described embodiments, the one or more MiMe loci for components of DNA double-strand breaks during meiotic recombination comprise PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof. In further variations of the above-described embodiments, one or more MiMe loci for components of sister chromatid cohesion during meiosis I include REC8, SWITCH1 / DYAD, or a combination thereof. In yet further variations of the above-described embodiments, one or more MiMe loci for components of progression through meiosis II include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof. In yet further variations of the above-described embodiments, one or more MiMe loci for components of progression through meiosis I include PS1, JASON, or a combination thereof.

[0091] In some embodiments, the genetically modified plant, plant part, or plant cell comprises (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. e allele and at least one non-MiMe allele (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1), and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more unique MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0092] In some embodiments, the genetically modified plant, plant part, or plant cell comprises: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; (iii) only MiMe alleles at one or more PAIR1 loci. have a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1), and (iv) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0093] In some embodiments, the genetically modified plant, plant part, or plant cell comprises (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; or (iii) only MiMe alleles at one or more PAIR1 loci. have a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele (wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1), and (iv) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0094] In some embodiments, the genetically modified plant, plant part, or plant cell has a partially complemented MiMe genotype that includes (i) a ps allele (wherein the genetically modified plant, plant part, or plant cell is heterozygous for the ps allele), (ii) an os allele (wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele), (iii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8), and (iv) only a MiMe allele at one or more SPO11-1 loci (wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1).

[0095] In some embodiments, the genetically modified plant, plant part, or plant cell has a partially complemented MiMe genotype that includes: (i) an os allele (wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele); (ii) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci (wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1); (iii) only MiMe alleles at one or more REC8 loci (wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8); and (iv) only MiMe alleles at one or more SPO11-1 loci (wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of the SPO11-1 locus).

[0096] In some embodiments of the above-described genetically modified plants, plant parts, or plant cells that may be combined with any of the preceding embodiments, the genetically modified plant, plant part, or plant cell is diploid, triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In additional embodiments that may be combined with any of the preceding embodiments, the genetically modified plant, plant part, or plant cell comprises two, three, four, or more haplotypes of the same or closely related plant species.In still further embodiments that may be combined with any of the preceding embodiments, the genetically modified plant, plant part, or plant cell is selected from the group consisting of potato, corn, banana, blueberry, blackberry, watermelon, cantaloupe, tomato, tomatillo, pepper, eggplant, grape, orange, lemon, lime, grapefruit, cucumber, squash, gourd, pumpkin, apple, pear, kiwi, pomegranate, mango, guava, papaya, avocado, stone fruit, date, fig, alfalfa, tobacco, cotton, clover, strawberry, cabbage, cucumber ... Rantz, cranberry, gooseberry, boysenberry, raspberry, artichoke, beet, potato, sweet potato, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yam, radish, horseradish, turnip, parsnip, rutabaga, yucca, corn, onion, shallot, leek, radish, garlic, chives, peanut, asparagus, sugarcane, cassava, brussels sprouts, cabbage, collard greens, kale, lettuce, chard, spinach, Pak choy, okra, cashew nuts, pineapple, celery, oats, birch, rapeseed, mustard, tea, hemp, safflower seeds, cedar, quinoa, chickpeas, citron, Satsuma mandarins, tangerines and mandarins, clementines, coffee, cola tree, hazelnuts, saffron, melons and cantaloupes, carrots, oil palm, teff, rubber rabbit brush, eucalyptus, fir, soybeans, sunflowers, hemlock trees, rubber trees, kenaf, barley, hops, walnuts, larch, lentils, flax, ryegrass, maple, spinach, The spices are derived from plants selected from the group consisting of ski, basil, olive, rice, millet, shepherd's purse, green beans, kidney beans, ground cherry, pine, pistachio nuts, peas, turfgrass, poplar, apricots, plums and prunes, almonds, nectarines, peas, cherries, roses, bramble, rye, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, wheat, broad beans, cowpeas, ginger, plantain, kohlrabi, broccoli, and cauliflower.In some embodiments that may be combined with the above-mentioned embodiments, the genetically modified plant, plant part, or plant cell is derived from a parthenocarpic plant. In certain embodiments that may be combined with any of the preceding embodiments, the genetically modified plant part is a non-regenerable plant part. In certain embodiments that may be combined with any of the preceding embodiments, the genetically modified plant cell is a non-regenerable plant cell. In certain embodiments that may be combined with any of the preceding embodiments, the plant part is a flower, pistil, leaf, stem, petiole, cutting, tissue, seed coat, ovule, pollen, tuber, root, rhizome, shoot, fruit, cotyledon, hypocotyl, protoplast, embryo, anther, or part thereof. In a variation of the above-mentioned embodiment, the genetically modified plant part is a seedless fruit.

[0097] In another aspect, provided herein is a processed plant product derived from any of the above-described embodiments of a genetically modified plant, plant part, or plant cell, wherein the processed plant product comprises a detectable amount of one or more MiMe alleles of the genetically modified plant, plant part, or plant cell. In some embodiments, the product is selected from the group consisting of plant biomass, oil, meal, food starch, syrup, animal feed, powder, flakes, bran, long fiber, rice hulls, processed seeds, puree, juice, juice concentrate, pulp, pomace, preserves, and sauces. In certain embodiments, the processed plant product is non-renewable. [Brief explanation of the drawings]

[0098] The present application can be understood by reference to the following description considered in conjunction with the accompanying drawings.

[0099] [Figure 1] Phylogenetic tree of REC8 protein sequences from dicotyledonous plants is shown.

[0100] [Figure 2] Phylogenetic tree of REC8 protein sequences from monocotyledonous plants is shown.

[0101] [Figure 3] Phylogenetic tree of SPO11-1 protein sequences from dicotyledonous plants is shown.

[0102] [Figure 4] Phylogenetic tree of SPO11-1 protein sequences from monocotyledonous plants.

[0103] [Figure 5] A phylogenetic tree of PAIR1 protein sequences from dicotyledonous plants is shown.

[0104] [Figure 6] Phylogenetic tree of PAIR1 protein sequences from monocotyledonous plants is shown.

[0105] [Figure 7] A phylogenetic tree of OSD1 protein sequences from dicotyledonous plants is shown.

[0106] [Figure 8] Phylogenetic tree of OSD1 protein sequences from monocotyledonous plants.

[0107] [Figure 9]

[0033] Figure 1 shows the plasmid map of pLDB3, which was used to introduce MiMe gene editing into Zea mays.

[0108] [Figure 10]

[0033] Figure 1 shows the plasmid map of pLDB11B, which was used to introduce MiMe gene editing into Zea mays.

[0109] [Figure 11]

[0033] Figure 1 shows the plasmid map of pLDB12B, which was used to introduce MiMe gene editing into Zea mays.

[0110] [Figure 12]

[0033] Figure 1 shows the plasmid map of pMEM4, which was used to introduce MiMe gene editing into Zea mays.

[0111] [Figure 13]

[0033] Figure 1 shows the plasmid map of pMEM6b, which was used to introduce MiMe gene editing into Zea mays.

[0112] [Figure 14]

[0033] Figure 1 shows the plasmid map of pOGZ2, which was used to introduce MiMe gene editing into Zea mays.

[0113] [Figure 15]

[0033] Figure 1 shows the plasmid map of pOGZ4, which was used to introduce MiMe gene editing into Zea mays.

[0114] [Figure 16] 10 depicts an embodiment in which homozygous gene editing is performed at the parental stage.

[0115] [Figure 17] 10 illustrates an embodiment in which the grandparents are inbred and homozygous gene editing is performed at the parental level.

[0116] [Figure 18] 10 depicts an embodiment in which heterozygous gene editing is performed at the grandparental stage.

[0117] [Figure 19] 10 illustrates an embodiment in which the grandparents are inbred and heterozygous gene edited at the grandparent stage.

[0118] [Figure 20] 1 illustrates an embodiment in which the MiMe loci are transmitted at the grandparental level.

[0119] [Figure 21] 1 illustrates an embodiment in which the grandparents are inbred and the MiMe locus is transmitted at the grandparent stage.

[0120] [Figure 22] 1 illustrates an embodiment in which the MiMe loci are transmitted at the great-grandparent level.

[0121] [Figure 23] 1 shows an embodiment in which unilateral editing results in sexual tetraploidization.

[0122] [Figure 24A] Figure 24A shows an embodiment in which complementation of one of the MiMe loci induces sterility in polyploid hybrid seeds. Figure 24A shows the generation of a plant with a first exemplary partially complemented MiMe genotype in which the MiMe loci are propagated at the parental stage, with each parent having a different set of edited MiMe loci. [Figure 24B] Figure 24B shows an embodiment in which complementation of one of the MiMe loci induces sterility in polyploid hybrid seeds. Figure 24B shows the generation of a plant with a second exemplary partially complemented MiMe genotype in which the MiMe loci are propagated at the parental stage, with each parent having a different set of edited MiMe loci. [Figure 24C] Figure 24C shows an embodiment in which complementation of one of the MiMe loci induces sterility in polyploid hybrid seeds. Figure 24D shows the generation of a plant with a third exemplary partially complemented MiMe genotype in which the MiMe loci are propagated at the parental stage, with each parent having a different set of edited MiMe loci.

[0123] [Figure 25A] Figure 25A shows the results of a guide RNA screening for editing in potato. Figure 25A shows the results of a screening in which the editing efficiency at four different genes (horizontal axis, gray boxes) is shown as the percentage of editing (vertical axis, percentage) at a selected set of protospacers (horizontal axis). From left to right, the potato orthologs of OSD1 ("StOsd1"), PAIR1 ("StPair1"), REC8 ("StRec8"), and SPO11-1 ("StSpo11-1") are listed. [Figure 25B]Figure 25B shows the results of a guide RNA screening for editing in potato. Figure 25B shows further results of a screen like Figure 25A, except the gene shown is the potato orthologue of CYCA1 ("StCyca1").

[0124] [Figure 26A] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited potato line is shown in Figure 26A, which shows a truncated, inactivated protein resulting from the insertion of a premature stop codon in the edited rec8 allele. [Figure 26B] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited potato line is shown. Figure 26B shows a truncated, inactivated protein resulting from the insertion of a premature stop codon in the edited cyca1 allele. [Figure 26C] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited potato line is shown. Figure 26C shows a truncated, inactivated protein resulting from the insertion of a premature stop codon in the edited spo11-1 allele. [Figure 26D] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited potato line is shown. Figure 26D shows an alignment of the edited "scar" nucleotide sequence of the edited rec8 allele (the bottom part is a continuation from the top part). [Figure 26E] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited potato line are shown in Figure 26E. Figure 26E shows an alignment of the edited "scar" nucleotide sequence of the edited cyca1 allele (the bottom part is a continuation from the top part). [Figure 26F] The resulting editing of the MiMe allele and disruption of the MiMe element in the edited potato line is shown. Figure 26F shows an alignment of the edited "scar" nucleotide sequence of the edited spo11-1 allele (the bottom part is a continuation from the top part).

[0125] [Figure 27A] Summary of genotyping results at 52 triallelic markers in the 19 progenies that make up Boosted Potato Population 1 (BPP1). The vertical axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The horizontal axis corresponds to the individual triallelic markers distributed across 12 separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legend. The coloring of each cell represents the particular configuration of haplotypes observed for that marker (where A=M18, B=DM, and C=M6). The cell with the "AABC" marker has three haplotypes. The genotypes of the parents are shown along the top row.

[0126] [Figure 27B] Summary of genotyping results at 60 tetraallelic markers in the 19 progenies comprising Boosted Potato Population 2 (BPP2). The vertical axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The horizontal axis corresponds to the individual tetraallelic markers distributed across 12 separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legend. The coloring of each cell represents the particular configuration of haplotypes observed for that marker (where A=DM, B=M6, and C=Atlantic haplotype 1 and D=Atlantic haplotype 2). The sample with the "ABCD" marker has four haplotypes. The parental genotypes are shown along the top row.

[0127] [Figure 27C]Summary of genotyping results at 50 triallelic markers in the 10 progenies that make up Boosted Potato Population 3 (BPP3). The vertical axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The horizontal axis corresponds to the individual triallelic markers distributed across 12 separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legend. The coloring of each cell represents the particular configuration of haplotypes observed for that marker (where A=M18, B=DM, and C=M6). Cells with markers "ABBC" have three haplotypes. The genotypes of the parents are shown along the top row.

[0128] [Figure 27D] Summary of genotyping results at 60 tetraallelic markers in the 12 progenies comprising Boosted Potato Population 4 (BPP4). The vertical axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The horizontal axis corresponds to the individual tetraallelic markers distributed across 12 separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legend. The coloring of each cell represents the specific composition of haplotypes observed for that marker (where A=DM, B=M6, and C=Atlantic haplotype 1 and D=Atlantic haplotype 2). The sample with the "ABCD" marker has four haplotypes. The parental genotypes are shown along the top row.

[0129] [Figure 27E]Summary of genotyping results at 60 tetraallelic markers in the eight progenies that make up Boosted Potato Population 5 (BPP5). The vertical axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The horizontal axis corresponds to the individual tetraallelic markers distributed across 12 separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legend. The coloring of each cell represents the specific composition of haplotypes observed for that marker (where A=DM, B=M6, and C=Atlantic haplotype 1 and D=Atlantic haplotype 2). The sample with the "ABCD" marker has four haplotypes. The parental genotypes are shown along the top row.

[0130] [Figure 28A] Photographs of one BPP1 potato plant ("BPP1 (Boost)") 12 days after planting, its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), its parent plants ("Non-MiMe Parent (PED-PR-CC-o)" and "MiMe Parent (PED-PR-AB-sp)"), and a commercially available elite tetraploid are shown. [Figure 28B] Measurement of visible leaf surface area is shown in Figure 28A, comparing the aerial surface area (cm2) of each plant in the photographs of Figure 28A using ImageJ software.

[0131] [Figure 28C] Photographs of three BPP1 potato plants ("BPP1 (Boost)") 12 days after planting, its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), its parent plants ("Non-MiMe Parent (PED-PR-CC-o)" and "MiMe Parent (PED-PR-AB-sp)"), and a commercially available elite tetraploid are shown. [Figure 28D]Measurement of visible leaf surface area is shown in Figure 28C, comparing the aerial surface area (cm2) of each plant in the photographs of Figure 28C using ImageJ software.

[0132] [Figure 28E] Photographs of one BPP1 potato plant ("BPP1 (Boost)") 19 days after planting, its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), its parent plants ("Non-MiMe Parent (PED-PR-CC-o)" and "MiMe Parent (PED-PR-AB-sp)"), and a commercially available elite tetraploid are shown. [Figure 28F] Measurement of visible leaf surface area is shown in Figure 28C, comparing the aerial surface area (cm2) of each plant in the photographs of Figure 28C using ImageJ software.

[0133] [Figure 28G] Photographs of one BPP1 potato plant ("BPP1 (Boost)") 26 days after planting, its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), its parent plants ("Non-MiMe Parent (PED-PR-CC-o)" and "MiMe Parent (PED-PR-AB-sp)"), and a commercially available elite tetraploid are shown. [Figure 28H] Measurement of visible leaf surface area is shown in Figure 28C, comparing the aerial surface area (cm2) of each plant in the photographs of Figure 28C using ImageJ software.

[0134] [Figure 28I]Photographs show six BPP1 potato plants (right, "BPP1") obtained from a cross between a non-MiMe parent plant (PED-PR-CC-o) and a MiMe parent plant (PED-PR-AB-sp) compared with six SPP2 potato plants (left, "SPP2") obtained from a cross between two non-MiMe parent plants (PED-PR-CC-o and PED-PR-AB). All plants are 16 days after planting. [Figure 28J] Measurements of visible leaf surface area are shown in Figure 281, comparing the aerial surface area (cm) of each plant in the photographs in Figure 281 using ImageJ software. The mean and standard deviation of the aerial surface area for each plant population are indicated on the graph by crosses and error bars, respectively.

[0135] [Figure 28K] Photographs show six BPP1 potato plants (right, "BPP1") obtained from a cross between a non-MiMe parent plant (PED-PR-CC-o) and a MiMe parent plant (PED-PR-AB-sp) compared with six SPP2 potato plants (left, "SPP2") obtained from a cross between two non-MiMe parent plants (PED-PR-CC-o and PED-PR-AB). All plants are 23 days after planting. [Figure 28L] Measurement of visible leaf surface area is shown in Figure 28K, comparing the aerial surface area (cm) of each plant in the photographs of Figure 28K using ImageJ software. The mean and standard deviation of the aerial surface area for each plant population are indicated on the graph by crosses and error bars, respectively.

[0136] [Figure 29A] Photographs of its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), parent plants ("MiMe Parent (PED-PR-AB-sp) and "MiMe Parent (PED-PR-EF-rso-1)"), and a BPP2 potato plant ("BPP2 (Boost)") adjacent to a commercially available elite tetraploid are shown. All plants are 23 days after planting.

[0137] [Figure 29B] Photographs of its grandparent plants ("Non-MiMe Grandparent (PED-PR-AA)" and "Non-MiMe Grandparent (PED-PR-BB)"), parent plants ("MiMe Parent (PED-PR-AB-sp)" and "MiMe Parent (PED-PR-EF-rso-1)"), and a BPP2 potato plant adjacent to a commercially available elite tetraploid ("BPP2 (Boost)") are shown. All plants are 23 days after planting.

[0138] [Figure 29C] Photographs of BPP2 potato plants ("BPP2 (Boost)", four haplotypes) adjacent to the tetraploids of each grandparent (4n) version ("4n version of non-MiMe grandparent (PED-PR-AA)", one haplotype" and "4n version of non-MiMe grandparent (PED-PR-BB)", one haplotype") and parent plants ("4n version of PED-PR-AA x PED-PR-BB", two haplotypes" and "4n version of dihaploid Atlantic", two haplotypes") are shown. All plants are 23 days after planting.

[0139] [Figure 29D] Photographs of BPP2 potato plants ("BPP2 (Boost)," four haplotypes) adjacent to tetraploid (4n) versions of their respective grandparent plants ("4n version of non-MiMe grandparent (PED-PR-AA) with one haplotype" and "4n version of non-MiMe grandparent (PED-PR-BB) with one haplotype") and parent plants ("4n version of PED-PR-AA x PED-PR-BB with two haplotypes" and "4n version of dihaploid Atlantic with two haplotypes"). All plants are 29 days after planting.

[0140] [Figure 29E]Photographs show nine BPP2 potato plants (right, "BPP2(PED-PR-EF-rso-1 x PED-PR-AB-sp") obtained by a cross between a MiMe parent plant (PED-PR-AB-sp) and a MiMe parent plant (PED-PR-EF-rso-1) compared with eight potato plants (left, "SPP1(PED-PR-EF-o x PED-PR-AABB") obtained by a cross between two non-MiMe parent plants (PED-PR-EF-o and PED-PR-AABB). One of the progeny plants from the non-MiMe cross failed to develop, which is why there are only eight instead of nine. All plants are 16 days after planting. [Figure 29F] Measurement of visible leaf surface area is shown in Figure 29E, comparing the aerial surface area (cm) of each plant in the photograph in Figure 29E using ImageJ software. The mean and standard deviation of the aerial surface area for each plant population are indicated on the graph by crosses and error bars, respectively.

[0141] [Figure 29G] Photographs show nine BPP2 potato plants (right, "BPP2(PED-PR-EF-rso-1 x PED-PR-AB-sp") obtained by a cross between a MiMe parent plant (PED-PR-AB-sp) and a MiMe parent plant (PED-PR-EF-rso-1) compared with eight potato plants (left, "SPP1(PED-PR-EF-o x PED-PR-AABB") obtained by a cross between two non-MiMe parent plants (PED-PR-EF-o and PED-PR-AABB). One of the progeny plants from the non-MiMe cross failed to develop, which is why there are only eight instead of nine. All plants are 23 days after planting. [Figure 29H] Measurements of visible leaf surface area are shown in Figure 29G, comparing the aerial surface area (cm) of each plant in the photographs of Figure 28E using ImageJ software. The mean and standard deviation of the aerial surface area for each plant population are indicated on the graph by crosses and error bars, respectively.

[0142] [Figure 29I] Photographs show eight BPP2 potato plants (right, "BPP2(PED-PR-EF-rso-1 x PED-PR-AB-sp") obtained by crossing a MiMe parent plant (PED-PR-AB-sp) with a MiMe parent plant (PED-PR-EF-rso-1) compared with eight potato plants (left, "SPP1(PED-PR-EF-o x PED-PR-AABB") obtained by crossing two non-MiMe parent plants (PED-PR-EF-o and PED-PR-AABB). One of the progeny from the non-MiMe cross failed to develop. This is why there were only eight instead of nine. Therefore, one of the BPP2 progeny was removed so that both populations had the same number of individuals. All plants are 29 days after planting.

[0143] [Figure 30A] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30A shows a matrix of pairwise identities, as estimated by Jaccard similarity coefficients of 64 genotyped molecular markers, among 19 tetraploid potato plants in Boosted Potato Population 1 (BPP1). [Figure 30B] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30B shows a matrix of pairwise identities, as estimated by Jaccard similarity coefficients of 52 genotyped molecular markers, among 19 tetraploid potato plants in Boosted Potato Population 2 (BPP2). [Figure 30C] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30C shows a matrix of pairwise identities estimated by Jaccard similarity coefficients of 47 genotyped molecular markers among 10 tetraploid potato plants in Boosted Potato Population 3 (BPP3). [Figure 30D] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30D shows a matrix showing pairwise identities, as estimated by Jaccard similarity coefficients, of 60 genotyped molecular markers among 12 tetraploid potato plants in Boosted Potato Population 4 (BPP4). [Figure 30E] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30E shows a matrix showing pairwise identities, as estimated by Jaccard similarity coefficients, of 60 genotyped molecular markers among eight tetraploid potato plants in Boosted Potato Population 5 (BPP5). [Figure 30F] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30F shows a matrix of pairwise identities estimated by Jaccard similarity coefficients of 56 genotyped molecular markers among seven tetraploid potato plants in Standard Potato Population 1 (SPP1). [Figure 30G] Plants grown from populations of polyploid seeds produced by the methods described herein show superior uniformity compared to a control population. Figure 30G shows a matrix of pairwise identities estimated by Jaccard similarity coefficients of 52 genotyped molecular markers among four tetraploid potato plants in Standard Potato Population 2 (SPP2).

[0144] [Figure 31A]Comparative measurements of tuber size of BPP1 and the cross to produce BPP1 are shown. Figure 31A shows images of tubers. From left to right, shown are tubers from the first grandparent plant ("Non-MiMe grandparent PED-PR-AA (doubled haploid DM1-3)") with an average tuber weight of 35.5 g, tubers from the second grandparent plant ("Non-MiMe grandparent PED-PR-BB (selfed M6)") with an average tuber weight of 5.2 g, tubers from the first parent plant ("MiMe parent (spo11-1 / ps) PED-PR-AB-sp") with an average tuber weight of 78.1 g, tubers from the second parent plant ("Non-MiMe parent PED-PR-CC-o") with an average tuber weight of 35.3 g, and tubers from the BPP1 plant ("Boost progeny BPP1") with an average tuber weight of 161.2 g. [Figure 31B] Figure 31B shows a comparative measurement of tuber size of BPP1 and the cross that produced BPP1. Figure 31B shows the plotted weight of the tubers shown in Figure 31A.

[0145] [Figure 32]

[0033] Figure 1 shows the plasmid map of pOGZ1, which was used to introduce MiMe gene editing into Zea mays.

[0146] [Figure 33A] Figure 33A shows the results of a guide RNA screening for editing in maize. Figure 33A shows the results of a screening in which the editing efficiency at four different genes (horizontal axis, gray boxes) is shown as the ratio of edited sequence reads compared to the wild type (vertical axis, percentage) at a selected set of protospacers (horizontal axis). From left to right, the maize orthologs of OSD1 on chromosome 2 ("ZmOsd1-chr2"), OSD1 on chromosome 5 ("ZmOsd1-chr5-1"), and duplicated OSD1 on chromosome 5 ("ZmOsd1-chr5-2"), CYCA1 on chromosome 3 ("ZmTAM-chr3"), and CYCA1 on chromosome 8 ("ZmTAM-chr8") are listed. [Figure 33B]Figure 33B shows the results of a guide RNA screening for editing in maize. Figure 33B shows further results of a screen like that in Figure 33A, except that the genes shown are the maize orthologues of PAIR1 ("ZmPair1-1" and "ZmPair1-9"), REC8 ("ZmRec8"), and SPO11-1 ("ZmSpo11-1").

[0147] [Figure 34A] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited corn line are shown in Figure 34A, which shows that four conserved amino acids in the REC8 protein are missing as a result of editing the rec8 allele. [Figure 34B] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited corn line is shown. Figure 34B shows a truncated, inactive OSD1 protein resulting from a frameshift edit that results in a premature stop codon in the edited osd1 allele. [Figure 34C] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited corn line are shown. Figure 34C shows a truncated, inactive SPO11-1 protein resulting from a frameshift edit that results in a premature stop codon in the edited spo11-1 allele. [Figure 34D] The resulting editing of the MiMe allele and disruption of the MiMe element in the edited corn line is shown. Figure 34D shows an alignment of the edited "scar" nucleotide sequence of the edited rec8 allele (the bottom part is a continuation from the top part). [Figure 34E] The resulting editing of the MiMe allele and disruption of the MiMe element in the edited corn line are shown. Figure 34E shows an alignment of the edited "scar" nucleotide sequence of the edited osd1 allele (the bottom part is a continuation from the top part). [Figure 34F]The resulting editing of the MiMe allele and disruption of the MiMe element in the edited corn line are shown. Figure 34F shows an alignment of the edited "scar" nucleotide sequence of the edited spo11-1 allele (the bottom part is a continuation from the top part).

[0148] [Figure 35] The expected pairwise identity (or percentage of alleles shared between genotypes, as estimated by the Jaccard similarity coefficient) of randomly selected individuals within each population is shown (SAP: Arabidopsis standard population, SPP1: potato standard population 1, SPP2: potato standard population 2, BAP1: boosted Arabidopsis standard population 1, BMP: boosted maize standard population, BPP1: boosted potato standard population 1, BPP2: boosted potato standard population 2, BPP3: boosted potato standard population 3, BPP4: boosted potato standard population 4, BPP5: boosted potato standard population 5). Diamonds represent the expected pairwise identity between genotyped plants in each population or the mean pairwise identity between genotyped plants in each population. Black bars are the median or second quartile. Boxes represent the interquartile range from the first to third quartile, respectively, and dashed whiskers indicate the minimum and maximum pairwise identities between genotyped individuals in each population.

[0149] [Figure 36A] 1 shows a matrix of pairwise identities estimated by Jaccard similarity coefficients of 44 genotyped molecular markers among 48 tetraploid maize plants in the Boosted Maize Population (BMP).

[0150] [Figure 36B]A summary of genotyping results at 44 triallelic markers in 48 progenies comprising the boosted corn population (BMP) is shown. The horizontal axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The vertical axis corresponds to the individual triallelic markers distributed across eight separate chromosomes. The coloring of each cell represents the specific configuration of haplotypes observed for that marker (where A = LH244, B = A188, and C = FFMM-AT6). A cell with a marker of "AABC" has three haplotypes. Marker design was limited to regions of the genome where heterozygous parental SNPs were present. No usable markers were found on chromosomes 2 or 10. Parental genotypes are shown along the leftmost column.

[0151] [Figure 37A] Examples of BMP plants are shown in Figure 37A, which shows multiple rows of BMP plants. [Figure 37B] Figure 37B shows a close-up of the right side of Figure 37A, which shows a close-up of three BMP plants. [Figure 37C] Examples of BMP plants are shown in Figure 37C. Figure 37C shows a healthy BMP plant that readily produces panicles. [Figure 37D] An example of a BMP plant is shown in Figure 37D. Figure 37D shows a close-up of the spike of a BMP plant as shown in Figure 37C.

[0152] [Figure 38] Results of a guide RNA screening for editing in A. thaliana are shown. Editing efficiency in four different genes (horizontal axis, gray boxes) is shown as the ratio of edited sequence reads compared to the wild type (vertical axis, percentage) at a selected set of protospacers (horizontal axis). From left to right, the A. thaliana orthologs of OSD1 ("AtOsd1(Col-0)"), PAIR1 ("AtPair1(Col-0)"), REC8 ("AtRec8(Col-0)"), and SPO11-1 ("AtSpo11-1(Col-0)") are listed. Black arrows indicate which sites were further investigated based on the guide RNA screening results.

[0153] [Figure 39A] The resulting editing of the MiMe alleles and disruption of the MiMe components in the edited Arabidopsis lines are shown. Figure 39A shows a truncated, inactivated protein due to a premature stop codon resulting from the edited osd1 allele. [Figure 39B] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited Arabidopsis line are shown. Figure 39B shows a truncated, inactivated protein resulting from the insertion of a premature stop codon in the edited spo11-1 allele. [Figure 39C] The resulting editing of MiMe alleles and disruption of MiMe components in edited Arabidopsis lines are shown. Figure 39C shows a truncated, inactivated protein due to a premature stop codon in one of the edited rec8 alleles and a deletion of three conserved amino acids due to the other edited rec8 allele. [Figure 39D] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited Arabidopsis line are shown. Figure 39D shows an alignment of the edited "scar" nucleotide sequence of the osd1 allele edited to the first target site (the bottom section is a continuation of the top section). [Figure 39E] The resulting editing of the MiMe allele and disruption of the MiMe component in the edited Arabidopsis line is shown. Figure 39E shows an alignment of the edited "scar" nucleotide sequence of the osd1 allele edited to the second target site (the bottom section is a continuation of the top section). [Figure 39F] The resulting editing of the MiMe alleles and disruption of the MiMe components in the edited Arabidopsis lines are shown. Figure 39F shows an alignment of the edited "scar" nucleotide sequences of the edited spo11-1 alleles (the bottom section is a continuation from the top section). [Figure 39G]The resulting editing of the MiMe alleles and disruption of the MiMe components in the edited Arabidopsis lines are shown. Figure 39G shows an alignment of the edited "scar" nucleotide sequences of the edited rec8 alleles. [Figure 39H] The resulting editing of the MiMe alleles and disruption of the MiMe components in the edited Arabidopsis lines are shown. Figure 39H shows an alignment of the edited "scar" nucleotide sequences of the edited pair1 alleles (the bottom part is a continuation from the top part).

[0154] [Figure 40A] Figure 40A shows a heatmap comparing the genotype distribution and degree of uniformity in the A. thaliana MiMe and control populations. Figure 40A shows a summary of genotyping results at 58 triallelic markers in the 99 progeny comprising Boosted Arabidopsis Population 1 (BAP1). The horizontal axis corresponds to the individual tetraploid progeny and the two diploid parent plants for reference. The vertical axis corresponds to the individual triallelic markers distributed across four separate chromosomes. When referring to axes, vertical and horizontal refer to the text in the respective figure legends. The coloring of each cell represents the specific configuration of haplotypes observed for that marker (where A = Shahdara, B = Col-0, and C = HR-10). Cells with "AABC" markers have three haplotypes. Marker design was limited to regions of the genome where heterozygous parental SNPs were present. No usable markers were found on chromosome 3. Parental genotypes are shown in the leftmost two columns. [Figure 40B]Figure 40B shows a heatmap comparing the genotype distribution and degree of uniformity in the A. thaliana MiMe and control populations. Figure 40B shows a summary of genotyping results at 57 triallelic markers in nine progenies of the Arabidopsis standard population (SAP, top). The vertical axis corresponds to individual tetraploid progenies and two tetraploid parent plants for reference. The horizontal axis corresponds to individual triallelic markers distributed across five separate chromosomes. The color of each cell represents the specific composition of haplotypes observed for that marker (where A = Shahdara, B = Col-0, and C = HR-10). Nine representative individuals of BAP1 (Figure 40A) are shown for comparison (bottom). [Figure 40C] Figure 40C shows a heatmap comparing the genotype distribution and degree of homogeneity in the MiMe and control populations of A. thaliana. Figure 40C shows a matrix depicting pairwise identity, as estimated by Jaccard similarity coefficients, of 57 genotyped molecular markers among nine tetraploid Arabidopsis plants in the Arabidopsis Standard Population (SAP). [Figure 40D] Figure 40D shows a heatmap comparing the genotype distribution and degree of homogeneity in the MiMe and control populations of A. thaliana. Figure 40C shows a matrix of pairwise identities estimated by Jaccard similarity coefficients of 58 genotyped molecular markers among 99 tetraploid Arabidopsis plants in Boosted Arabidopsis Population 1 (BAP1).

[0155] [Figure 41A] Figure 41A shows a top-down view of a BAP1 plant 48 days after planting. [Figure 41B] Figure 41B shows a subset of the BAP1 plants in Figure 41A in a closer and oblique view, also 48 days after planting.

[0156] [Figure 42A]Figure 42A shows the formation of parthenocarpic (seedless) fruit in Arabidopsis MiMe plants and controls. Figure 42A shows seedless fruit from BAP1 plants whose pistils were treated with gibberellic acid (GA3), untreated, or mock-treated to induce fruit enlargement, compared to fruit obtained from treated or mock-treated pistils of Arabidopsis fertile control plants. [Figure 42B] Figure 42B shows the formation of parthenocarpic (seedless) fruit in Arabidopsis MiMe plants and controls. Figure 42B shows a comparison of the average number of seeds per silique (vertical axis) between BAP1 plants, a doubled version of the MiMe parent plant PED-AR-BC (doubled as "PED-AR-BCBC"), and a doubled version of the MiMe parent plant PED-AR-AA (doubled as "PED-AR-AAAA") (all located along the horizontal axis). The population mean and standard deviation are indicated on the graph by crosses and error bars, respectively. [Figure 42C] Figure 42C shows parthenocarpic (seedless) fruit formation in Arabidopsis MiMe plants and controls. Figure 42C shows a comparison of silique length (vertical axis) among the same plant groups (horizontal axis) in Figure 42B. The length of the fruit (silique) resulting from GA3-treated, mock-treated ("mock"), and untreated pistils was measured across each plant group 8 days after GA3 application. The population mean and standard deviation are indicated on the graph by crosses and error bars, respectively. [Figure 42D] Figure 42D shows the formation of parthenocarpic (seedless) fruit in Arabidopsis MiMe plants and controls. Figure 42D shows a comparison of the average number of seeds per silique (vertical axis) between BAP2 plants, a doubled version of the MiMe parent plant PED-AR-BC (doubled as "PED-AR-BCBC"), and a doubled version of the MiMe parent plant PED-AR-DE (doubled as "PED-AR-DEDE") (all located along the horizontal axis). The population mean and standard deviation are indicated on the graph by crosses and error bars, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0157] The following description is provided to enable those skilled in the art to make and use various embodiments. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications of the examples described herein will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Accordingly, the various embodiments are not intended to be limited to the examples described and shown herein, but are intended to be accorded the scope consistent with the appended claims.

[0158] overview In one aspect, described herein is a population of polyploid seeds comprising three or more haplotypes of plants of the same or closely related species, wherein at least 50% of the polyploid seed population is genetically uniform, and the population was obtained from a single plant or set of plants, such as a set of genetically uniform F1 hybrids. In some embodiments, the polyploid seed population comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise three or more haplotypes of plants of the same or closely related species. The genetic uniformity of the seeds in the population addresses a long-felt need for a genetically uniform population of polyploid seeds comprising three or more haplotypes with improved hybrid vigor performance compared to pairs of haplotypes present in existing hybrid plants. In some embodiments, the polyploid seed population and / or the genetically uniform polyploid seed subpopulation comprises one or more genetic modifications that result in reduced expression of one or more MiMe loci. The polyploid seed population and / or genetically uniform polyploid seed subpopulation may have a complete or partial MiMe genotype that includes a MiMe allele that confers reduced expression of one or more MiMe component MiMe loci. In certain embodiments, germination of seeds from the polyploid seed population and / or genetically uniform polyploid seed subpopulation results in sterile plants that produce non-viable gametes, seedless fruit, or a combination thereof.

[0159] In another aspect, provided herein are methods for producing a population of polyploid seeds comprising three or more haplotypes, wherein at least 50% of the population of polyploid seeds are genetically uniform. In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise three or more haplotypes of plants of the same or closely related species. In some embodiments, the method includes (a) providing clonal gametes from a pair of MiMe parent plants that collectively comprise three or more haplotypes, and (b) crossing the clonal gametes to produce a population of polyploid seeds. In other embodiments, the method includes (a) providing clonal gametes from a MiMe parent plant, (b) providing haploid (e.g., haploid, dihaploid, or higher ploidy) gametes from a homozygous non-MiMe parent plant, and (c) crossing the clonal gametes with haploid (e.g., haploid) gametes to produce a population of the polyploid seeds.

[0160] In yet another aspect, provided herein are methods for breeding polyploid hybrid plant lines comprising three or more haplotypes, the methods comprising obtaining a set of plant lines, breeding the lines using conventional plant breeding methods to produce a set of candidate plant lines, and selecting two or more candidate lines for crossing that collectively comprise three or more haplotypes. In some embodiments, after selecting the candidate lines, the method further comprises generating two MiMe parent plants from the two or more candidate lines, providing clonal gametes from each of the MiMe parent plants, and crossing the clonal gametes to produce hybrid polyploid seeds comprising three or more haplotypes. In alternative embodiments, after selecting candidate lines, the method further comprises generating a single MiMe parent plant from one of the two or more candidate lines, providing clonal gametes from the MiMe parent plant, providing haploid (e.g., haploid) gametes from a homozygous non-MiMe parent plant of one of the two or more candidate lines, and crossing the clonal gametes with the haploid (e.g., haploid) gametes to produce hybrid polyploid seeds. In some embodiments, after crossing the clonal gametes or crossing the clonal gametes with haploid (e.g., haploid) gametes, the method further comprises cultivating the hybrid polyploid seeds to produce hybrid polyploid plants and evaluating one or more characteristics of the hybrid polyploid plants.

[0161] In another aspect, described herein is a polyploid seed population comprising a partially complemented MiMe genotype, wherein at least 50% of the polyploid seed population is genetically uniform, and the population was obtained from a single plant or a set of plants, such as a set of genetically uniform F1 hybrids. In some embodiments, the polyploid seed population comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform seeds comprise a partially complemented MiMe genotype. Polyploid seeds comprising a partially complemented MiMe genotype may comprise one, two, three, or more haplotypes. The partially complemented MiMe genotype of a polyploid seed population results in plants that do not have a wild-type meiotic phenotype or a MiMe phenotype. Thus, in some embodiments, germination of seeds from a polyploid seed population or a genetically uniform polyploid seed subpopulation results in plants that produce inviable gametes. In certain embodiments, the polyploid seeds are derived from parthenocarpic plant species and result in plants that produce seedless fruit. The genetic uniformity of the seeds in the population addresses a long-felt need for a genetically uniform population of polyploid seeds of plants, including parthenocarpic crops that produce seedless fruit. In some embodiments, the partially complemented MiMe genotype comprises (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of the second MiMe component. In certain embodiments, the partially complemented MiMe genotype further comprises (c) either (i) only MiMe alleles at one or more MiMe loci of the third MiMe component, or (ii) one or more MiMe alleles and one or more non-MiMe alleles at the first MiMe locus of the third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at the second MiMe locus of the third MiMe component.

[0162] In another aspect, provided herein are methods for producing a population of polyploid seeds comprising a partially complemented MiMe genotype, wherein at least 50% of the polyploid seed population is genetically uniform. In some embodiments, the polyploid seed population comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform seeds comprise a partially complemented MiMe genotype. The polyploid seeds comprising a partially complemented MiMe genotype may comprise one, two, three, or more haplotypes. In some embodiments, the method comprises: (a) providing clonal gametes from a first MiMe parent plant; (b) providing clonal gametes from a second MiMe parent plant; and (c) crossing the clonal gametes to produce a population of polyploid seeds comprising a partially complemented MiMe genotype. In some embodiments, a first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component, and a second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, and only MiMe alleles at the second MiMe locus of the second MiMe component. In certain embodiments, at least one of the MiMe loci of the first MiMe parent plant that has only MiMe alleles of the first MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only MiMe alleles of the first MiMe component. In some embodiments, the first and second MiMe parent plants further have only a MiMe allele at one or more MiMe loci of a third MiMe component, wherein the one or more MiMe loci of the first and second MiMe parent plants that have only a MiMe allele of the third MiMe component are the same or different.

[0163] In yet another aspect, provided herein is a method of breeding a polyploid plant, the method comprising obtaining a set of plant lines, breeding the lines using conventional plant breeding methods to produce a set of candidate lines of the plant, and selecting two or more candidate lines for crossing. In some embodiments, after selecting the candidate lines, the method further comprises generating two MiMe parent plants from the two or more candidate lines. In some embodiments, a first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component, and a second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, and only MiMe alleles at the second MiMe locus of the second MiMe component. In certain embodiments, at least one of the MiMe loci of the first MiMe parent plant that has only MiMe alleles of the first MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only MiMe alleles of the first MiMe component. In some embodiments, the first and second MiMe parent plants further have only a MiMe allele at one or more MiMe loci of a third MiMe component, wherein the one or more MiMe loci of the first and second MiMe parent plants that have only a MiMe allele of the third MiMe component are the same or different. In some embodiments, the method further includes providing clonal gametes from each of the MiMe parent plants, crossing the clonal gametes to produce polyploid seeds, cultivating the polyploid seeds to produce polyploid plants, and evaluating one or more traits of the polyploid plants.

[0164] In some variations of the breeding method, the method may further include repeating the steps of the method using one or more characteristics of the evaluated hybrid polyploid plants to guide line breeding, candidate line selection, or both. In additional variations, the method may further include organizing the set of lines into three or more heterosis groups, where each heterosis group includes haplotypes, the haplotypes being classified based on observed or predicted heterosis performance when combined in a hybrid polyploid plant. This method allows for the definitive combination of three or more haplotypes in polyploid plants, thereby addressing the need for a plant breeding method that produces predictable results in a shorter timescale than that required by traditional breeding methods.

[0165] definition As used herein, the term "plant" includes a whole plant or any part or derivative thereof, such as a plant organ (e.g., harvested or unharvested flowers, leaves, etc.), plant cell, plant protoplast, plant cell or tissue culture capable of regenerating a whole plant, regenerable or non-regenerable plant cell, plant callus, plant cell mass, and intact plant cells or plant parts within a plant, such as embryos, pollen, ovules, ovaries (e.g., harvested tissue or organs), flowers, leaves, seeds, tubers, clonally propagated plants, roots, stems, cotyledons, hypocotyls, root tips, etc. Plant parts or derivatives thereof may also include encapsulated forms of any of the above plant parts, such as alginate-encapsulated shoot meristems, nodes, stolon tips, etc. in artificial seeds. Any developmental stage, such as seedlings, immature plants, and mature plants, is also included.

[0166] As used herein, "potato" typically refers to the species Solanum tuberosum. Furthermore, it will be readily apparent to those skilled in the art that some varieties of Solanum tuberosum contain introgression from closely related Solanum species, and that such varieties are still considered Solanum tuberosum unless otherwise noted. The terms "potato" and "potato plant" include whole potato plants or any part or derivative thereof, such as plant organs (e.g., harvested or unharvested flowers, leaves, etc.), plant cells, plant protoplasts, plant cell or tissue cultures capable of regenerating whole plants, regenerable or non-regenerable plant cells, plant callus, plant cell mass, and intact plant cells or plant parts within plants, such as embryos, pollen, ovules, ovaries (e.g., harvested tissues or organs), flowers, leaves, seeds, tubers, clonally propagated plants, roots, stems, cotyledons, hypocotyls, root tips, meristems, nodes, stolon tips, etc. Potato plant parts or derivatives thereof may also include any of the above-mentioned plant parts in encapsulated form, such as alginate-encapsulated shoot meristems, nodes, stolon tips, etc. in artificial seeds. Any developmental stage is also included, such as seedlings, immature plants, and mature plants.

[0167] As used herein, the terms "corn" and "corn plant" include whole corn plants or any part or derivative thereof, such as plant organs (e.g., harvested or unharvested flowers, leaves, etc.), plant cells, plant protoplasts, plant cell or tissue cultures capable of regenerating whole plants, regenerable or non-regenerable plant cells, plant callus, plant cell mass, and intact plant cells or plant parts within a plant, such as embryos, pollen, ovules, ovaries (e.g., harvested tissues or organs), flowers, leaves, seeds, clonally propagated plants, roots, stems, cotyledons, hypocotyls, root tips, etc. Plant parts or derivatives thereof can also include encapsulated forms of any of the above plant parts, such as alginate-encapsulated shoot meristems, nodes, stolon tips, etc. in artificial seeds. Any developmental stage, such as seeds, seedlings, immature plants, and mature plants, is also included. As used herein, the term "non-regenerable" generally refers to a corn plant part, plant cell, processed corn product, or portion of any of the foregoing that cannot be induced to form a whole corn plant or cannot be induced to form a whole corn plant capable of sexual and / or asexual reproduction.

[0168] As used herein, the term "seed" refers to the true seed, not a separate plant part that is typically used for propagation. For example, as used herein, the term "potato seed" refers to the true potato seed, not the potato tuber.

[0169] As used herein, "parthenocarpic" generally refers to a plant or crop in which fruit development can proceed independently of pollination, fertilization, and / or seed development. Parthenocarpic plants can produce seedless fruit in a process commonly known as parthenocarpy, which is known in the art and described herein.

[0170] As used herein, "seedless plants" refers to plants or crops whose fruit typically contains inviable and / or underdeveloped seeds. As used herein, seedless plants may or may not require pollen or fertilization to stimulate fruit development. Fruit development may or may not involve seed initiation and cessation, leaving incompletely developed seeds. This process is commonly known to occur in plants such as seedless bananas, seedless table grapes, and seedless watermelons, by way of example only. As used herein, "seedless" may refer to incomplete seed development, lack of seed production, or otherwise nonviable seeds. Seedless plants may also refer to plants that are unable to produce fruit or seeds at all. For example, in crops where seed development is required for fruit development, failure to form viable eggs, sperm, or failure to fertilize may result in no seeds or fruit.

[0171] As used herein, the term "non-regenerable" generally refers to a plant part, plant cell, plant product, or portion of any of the foregoing that cannot be induced to form a whole plant or cannot be induced to form a whole plant capable of sexual and / or asexual reproduction.

[0172] As used herein, "ploidy" refers to the number of complete chromosome sets in a cell or organism. Ploidy can be annotated using "n" as the unit of complete chromosome set. For example, a cell or organism with a single chromosome set can be referred to as "1n", or a single chromosome set itself can be referred to as "1n". A diploid cell or organism with two sets of chromosomes can be referred to as "2n", a triploid cell or organism with three sets of chromosomes can be referred to as "3n", and so on.

[0173] As used herein, "haploid" refers to a cell or organism having a ploidy of 1n.

[0174] As used herein, "diploid" refers to a cell or organism having a ploidy of 2n.

[0175] As used herein, "polyploid" refers to a cell or organism having a ploidy greater than 2n. "Polyploid" can refer to an organism that is triploid (3n), tetraploid (4n), pentaploid (5n), hexaploid (6n), octaploid (8n), 7ploid (7n), or of a higher order of ploidy (greater than 8n).

[0176] As used herein, "allele" refers to one of two or more alternative forms of a single gene or locus in a genome. As used herein, "monoallelic" typically refers to the presence of a single allele at a given locus or set of loci within a cell or organism. As used herein, "biallelic" typically refers to the presence of two different alleles at a given locus or set of loci within a cell or organism. As used herein, "multiallelic" typically refers to the presence of three or more alleles at a given locus or set of loci within a cell or organism.

[0177] As used herein, "haplotype" refers to a distinct 1n set of chromosomes with a unique set of alleles. As used herein, each haplotype differs from other haplotypes in that it contains a set of alleles that confers a unique set of characteristics not conferred by other haplotypes. As used herein, a feature of the present disclosure is that each distinct haplotype need not be inherited from a different parent; a polyploid of the present disclosure may contain three or more haplotypes inherited from two parents. As used herein, a "monoallelic plant" typically refers to a plant lineage containing a single haplotype, a "biallelic plant" typically refers to a plant lineage containing two haplotypes, and a "multiallelic plant" typically refers to a plant lineage containing three or more haplotypes. In the case of allopolyploid plants containing multiple subgenomes with little or no recombination between them, the term "three or more haplotypes" as used herein typically refers to three or more haplotypes of the same subgenome.

[0178] As used herein, "clone" refers to a DNA entity that is substantially identical to another DNA entity, or a set of cells or organisms that contain such DNA. For example, mitosis results in two clone genomes contained in two clone cells. Due to random errors in natural DNA replication, clone DNA entities, clone cells, or clone organisms may not be completely identical. "Clone" can refer to two genomes that are not completely identical in sequence but contain the same set of alleles.

[0179] As used herein, "genetically homogeneous" typically refers to a set of individual plants, plant parts (e.g., seeds), or plant cells whose genomes are identical or clonal across at least 80% of loci. The genetic homogeneity of a set of individual plants, plant parts (e.g., seeds), or plant cells can be measured using methods known in the art and described herein. For example, a set of genetic markers can be identified and used to determine the estimated pairwise identity of a pair of individuals using the Jaccard similarity coefficient, or to determine the average pairwise genetic homogeneity of a population of individuals. For example, a genetically homogeneous plant or seed population may be comprised of plants or seeds having genomes that are identical to one another across at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the analyzed genetic markers, or may be comprised of seeds having an average pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity coefficient. Additionally, each pair of seeds in a genetically homogeneous plant or seed population may have genomes that are at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% pairwise identical, as measured by the Jaccard similarity coefficient.

[0180] As used herein, "expression" and "expression level" refer to the relative or absolute amount of a functional gene product present in a cell. As used herein, "gene product" includes, but is not limited to, nucleic acids (e.g., RNA), post-transcriptionally modified nucleic acids (e.g., spliced ​​RNA, polyadenylated mRNA), proteins (e.g., enzymes, structural proteins, etc.), and post-translationally modified proteins (e.g., glycoproteins, lipoproteins, etc.). The function of a gene product refers to the unmodified, uninhibited wild-type function of the gene product. As used herein, "reduced expression" refers to the relative decrease in the amount of a functional gene product of a gene or locus, such as a MiMe locus, present in a cell. Decreased expression can refer to a decrease in the total amount of a gene product present in a cell (e.g., a decrease in the amount of a protein), or a decrease in the amount of a functional gene product present in a cell (e.g., a decrease in the percentage of a protein with wild-type function, e.g., a change in the activity of the protein), or a decrease in the function of a gene product present in a cell (e.g., a decrease in the activity of a protein compared to a protein with wild-type function, e.g., elimination of activity). The reduction in expression can be a reduction in expression of a gene product encoded at a particular genomic locus. The reduction in expression also encompasses "non-expression" and "elimination of expression." As used herein, "non-expression" or "elimination of expression" refers to the absence of a functional gene product present in a cell, or an expression level insufficient to detect the gene product in the cell, or an expression level insufficient to result in the function of the gene product in the cell, or an activity level insufficient to result in detectable activity of the gene product in the cell.

[0181] As used herein, " homozygous " refers to a cell or organism in which all sets of chromosomes code the same allele or set of alleles at a specific chromosomal locus, a set of chromosomal loci, or all chromosomal loci.For example, a triploid cell or organism that has the same allele at a specific locus of all three sets of chromosomes is homozygous for that allele.An organism can be homozygous for a specific allele or set of alleles at a specific chromosomal locus or a set of chromosomal loci, or an organism can be homozygous for a haplotype.For example, a triploid cell or organism that contains three copies of the same haplotype is homozygous for that haplotype.As used herein, " homozygous plant " usually refers to an inbred plant or plant line, a single-allelic plant or plant line, or a plant or plant line that is homozygous at all loci in its genome.

[0182] As used herein, "heterozygote" refers to a cell or organism in which at least one set of chromosomes encodes an allele or set of alleles at a particular chromosomal locus or set of chromosomal loci, and the allele or set of alleles is different from that of other sets of chromosomes within the cell or organism. For example, a triploid cell or organism that has allele a1 at locus A of two sets of chromosomes and allele a2 at locus A of a third set of chromosomes is heterozygous for alleles a1 and a2. An organism can be heterozygous for a particular set of alleles at a particular chromosomal locus or set of chromosomal loci, or an organism can be heterozygous for a haplotype. For example, a triploid cell or organism containing two copies of a first haplotype and one copy of a second haplotype is heterozygous for the first and second haplotypes. As used herein, a "heterozygous plant" typically refers to a biallelic or multiallelic plant or plant line containing two or more haplotypes.

[0183] As used herein, "crossing" refers to the act of forming a zygote from the gametes of two different plants or plant lines. Crossing can refer to using pollen from a plant or plant line to pollinate a different plant or plant line.

[0184] As used herein, "closely related plants" refers to two or more species that, when crossed, produce viable seed.

[0185] As used herein, "hybrid" refers to a plant that contains two or more haplotypes derived from plants of the same or closely related species.

[0186] As used herein, "F1 hybrid" refers to a F1 hybrid seed or plant resulting from the crossing of parents containing two or more haplotypes. For clarity, this refers to the F1 hybrid of a cross, not the F1 hybrid of a hybrid of crosses.

[0187] As used herein, "hybrid vigor performance" refers to the ability of a set of two or more haplotypes to confer certain desired characteristics when combined in a hybrid plant. Desirable characteristics of hybrid vigor performance may include, but are not limited to, plant size, hardiness, fruit or grain yield, and the like.

[0188] As used herein, "MiMe" generally refers to a plant phenotype in which the wild-type meiotic phenotype of the plant is disrupted to result in the formation of female clonal gametes and / or male clonal gametes. "MiMe" may refer to any of several known methods for promoting the formation of female and / or male clonal gametes in plants, including, but not limited to, mitosis instead of meiosis as disclosed in d'Erfurth et al. (2009. Turning meiosis into mitosis. PLoS Biol 7, e1000124), and first division restitution without crossing over (FDR-NCO) as disclosed in Peloquin et al. (1999. Meiotic mutants in potato: valuable variants. Genetics 153:1493-1499), a prime example of FDR-NCO being the first division restitution without crossing over (FDR-NCO) as disclosed in Brownfield and Kohler (2010. Unreduced gamete formation in plants: mechanisms and prospects. J Exp Bot 62:5, 1659-1668).

[0189] In organisms with a wild-type meiotic phenotype, meiosis of germline cells results in haploid gametes. As used herein, "haploid" typically refers to a cell or organism with half the ploidy of the parent organism. As used herein, "haploid gamete" typically refers to a gamete cell with half the ploidy of the parent organism. For example, in a diploid (2n) organism with a wild-type meiotic phenotype, meiosis of germline cells results in 1n haploid gametes. In another example, in a tetraploid (4n) organism with a wild-type meiotic phenotype, meiosis of germline cells results in 2n haploid gametes. As used herein, a "non-MiMe parent plant" typically refers to a plant with a wild-type meiotic phenotype in which meiosis of germline cells results in haploid gametes (pollen and egg cells). As used herein, a "homozygous non-MiMe parent plant" typically refers to an inbred non-MiMe parent, a monoallelic non-MiMe parent plant, or a non-MiMe parent plant that is homozygous for all loci in its genome. Homozygous non-MiMe parent plants can be produced by inbreeding, production of doubled haploid lines (e.g., doubled haploid lines), or any other method known in the art for generating plant lines with a high degree of homozygosity.

[0190] In plants with the MiMe phenotype, meiosis in male and / or female germline cells is replaced by a mitosis-like process that results in clonal gametes. As used herein, "clonal gametes" refer to gametes that typically contain unrecombined, unreduced copies of the parent plant's genome and therefore have the same ploidy as the parent plant and are generally genetically identical to the parent plant. Clonal gametes are generated when the germline cells of the parent plant do not undergo the recombination that they undergo in the normal meiotic process and also undergo first-division reversion or second-division reversion, thereby resulting in unreduced gametes. As a result, clonal gametes are typically unreduced and unrecombined, and therefore generally genetically identical to the parent plant. For example, in diploid (2n) plants with the MiMe phenotype, germline cells undergo mitosis instead of meiosis, which typically results in unrecombined 2n gametes, i.e., clonal gametes. In another example, in tetraploid (4n) plants with the MiMe phenotype, germline cells undergo mitosis instead of meiosis, which typically results in non-recombinant 4n gametes, i.e., clonal gametes, which may refer to male clonal gametes, male clonal gametes, or a combination thereof.

[0191] As used herein, "unreduced, non-clonal gametes" typically refer to gametes that contain an unreduced but recombined copy of a parent plant's genome and thus have the same ploidy as the parent plant but are not genetically identical to the parent plant. Unreduced, non-clonal gametes are produced when germline cells of a parent plant undergo the recombination that they undergo in the normal meiotic process but undergo first- or second-division reversion, resulting in unreduced gametes. Thus, even though unreduced, non-clonal gametes are unreduced, they are the result of normal recombination processes and therefore are not genetically identical to the parent plant. For example, germline cells of a diploid (2n) plant that undergo normal recombination processes but undergo first- or second-division reversion result in recombined 2n gametes, i.e., unreduced, non-clonal gametes. In another example, germline cells of a tetraploid (4n) plant that undergo normal recombination processes but undergo first- or second-division reversion result in recombined 4n gametes, i.e., unreduced, non-clonal gametes. Unreduced non-clonal gametes may refer to female clonal gametes, male clonal gametes, or a combination thereof.

[0192] As used herein, "MiMe components" generally refer to gene functions that contribute to a MiMe phenotype, including, but not limited to, genes and gene products involved in meiosis that can be modified or altered to disrupt the wild-type meiotic phenotype in a manner appropriate for MiMe-mediated formation of cloned female gametes and / or cloned male gametes. MiMe components include (1) components of sister chromatid cohesion during meiosis I, (2) components of DNA double-strand breaks during meiotic recombination, (3) components of progression through meiosis II, and (4) components of progression through meiosis I. Generally, each MiMe component comprises one or more MiMe loci, which are described in more detail below. Furthermore, each MiMe locus typically may have MiMe alleles and non-MiMe alleles.

[0193] As used herein, a "MiMe allele" generally refers to an allele at a MiMe locus that disrupts the normal meiotic function of a MiMe component (e.g., an allele that interferes with sister chromatid cohesion during the first division of meiosis). A MiMe allele can be a naturally occurring MiMe allele or can be introduced into a plant line by genetic modification using the methods described herein.

[0194] As used herein, a "non-MiMe allele" refers to any allele that normally contributes to the wild-type function of a MiMe component and therefore does not contribute to conferring a MiMe phenotype to a plant. A non-MiMe allele normally refers to an allele at a MiMe locus that contributes to the wild-type meiotic function of a MiMe component (e.g., an allele that provides the wild-type function that contributes to sister chromatid cohesion during the first division of meiosis).

[0195] As used herein, "complete MiMe genotype" generally refers to any set of alleles that confer a MiMe phenotype to a plant. The individual alleles that make up a complete MiMe genotype are referred to as MiMe alleles. A complete MiMe genotype can be naturally occurring in a plant or can be introduced, for example, by plant breeding, transgenic techniques, gene editing techniques, or any combination thereof, to introduce one or more naturally occurring alleles, non-natural alleles, or combinations thereof. A complete MiMe genotype can include any number of MiMe alleles that result in a MiMe phenotype, for example, one, two, three, or more MiMe alleles. As used herein, "MiMe locus" and "MiMe loci" generally refer to any chromosomal locus or chromosomal loci that may be the site of a MiMe allele, including genes and intergenic loci. A MiMe locus or MiMe loci can correspond to a particular MiMe component, for example, if the MiMe locus encodes a gene product of the MiMe component. A complete MiMe genotype can contain MiMe alleles at any number of MiMe loci, for example, one, two, three, or more MiMe loci. A complete MiMe genotype can contain different alleles at the same MiMe locus on different sets of chromosomes and need not be homozygous to confer a MiMe phenotype. For example, a diploid plant with a complete MiMe genotype can have two different REC8 alleles, each of which reduces or eliminates the expression or activity of REC8, such that the plant has two MiMe alleles for REC8 and thereby exhibits disruption of sister chromatid cohesion during the first division of meiosis. Specific examples of complete MiMe genotypes are described in detail herein.

[0196] As used herein, a "partial MiMe genotype" typically refers to a set of alleles, including both MiMe alleles and non-MiMe alleles, at one or more MiMe loci, such that a plant with the partial MiMe genotype exhibits a wild-type meiotic phenotype. Two plants with compatible partial MiMe genotypes can be crossed to produce F1 progeny, each of which exhibits a wild-type meiotic phenotype and has a complete MiMe genotype and, therefore, a MiMe phenotype. As used herein, a "compatible partial MiMe genotype" typically refers to two or more partial MiMe genotypes that contain a set of MiMe alleles at the same MiMe locus. For example, a partial MiMe genotype containing MiMe alleles at REC8, SPO11-1, and OSD1 is compatible with another partial MiMe genotype containing the same or different MiMe alleles at REC8, SPO11-1, and OSD1. To generate a complete MiMe genotype and confer a MiMe phenotype to F1 progeny, a MiMe allele of a partial MiMe genotype can be combined in a single cross with a MiMe allele of the same or a different partial MiMe genotype. Generally, when a MiMe allele and a non-MiMe allele are referred to together, they are alleles at the same MiMe locus. A partial MiMe genotype can be naturally occurring in a plant, or can be introduced, for example, by plant breeding, transgenic technology, gene editing technology, or any combination thereof, to introduce one or more naturally occurring alleles, non-natural alleles, or combinations thereof. A partial MiMe genotype can contain any number of alleles, for example, one, two, three, or more alleles. Furthermore, a partial MiMe genotype can contain MiMe alleles at any number of MiMe loci, for example, one, two, three, or more MiMe loci. Specific examples of partial MiMe genotypes are described in detail herein.

[0197] As used herein, a "partially complemented MiMe genotype" typically refers to a set of alleles that includes only a MiMe allele at each of one or more MiMe loci of a first MiMe component, both a MiMe and a non-MiMe allele at the first MiMe locus of a second MiMe component, and both a MiMe and a non-MiMe allele at the second MiMe locus of the second MiMe component. A plant with a partially complemented MiMe genotype typically does not exhibit a wild-type meiotic phenotype because the first MiMe component has only a MiMe allele at each of one or more MiMe loci, thereby disrupting wild-type meiosis. The plant also does not exhibit a MiMe phenotype due to the complementation of the MiMe allele by a non-MiMe allele at each of the first and second MiMe loci of the second MiMe component. Thus, a plant with a partially complemented MiMe genotype exhibits neither a wild-type meiotic phenotype nor a MiMe phenotype. A partially complemented MiMe genotype may also contain a MiMe allele for a third MiMe component, e.g., only a MiMe allele at each of one or more MiMe loci of the third MiMe component, or both a MiMe and a non-MiMe allele at a first MiMe locus of the third MiMe component and both a MiMe and a non-MiMe allele at a second MiMe locus of the third MiMe component. As used herein, a plant or genotype "containing only MiMe alleles at MiMe loci" is a plant or genotype in which each set of chromosomes has a MiMe allele at that locus, thus conferring reduced expression (including non-expression or altered activity) of a functional gene product at that locus. Exemplary partially complemented MiMe genotypes are shown in Figures 24A-24C and described in detail herein. The MiMe alleles at each MiMe locus that has only the MiMe allele of the first MiMe component can include any number of different MiMe alleles on different sets of chromosomes and do not have to be homozygous as long as no non-MiMe alleles are present at that locus on any set of chromosomes.A partially complemented MiMe genotype can include, for example, one, two, three, or more MiMe alleles and one, two, three, or more non-MiMe alleles at each of the first and second MiMe loci of a second MiMe component, so long as there is at least one MiMe allele and at least one non-MiMe allele at each of the first and second MiMe loci of a second MiMe component. Furthermore, a partially complemented MiMe genotype can include MiMe alleles at more than three MiMe loci, for example, four, five, or more MiMe loci. Specific examples of partially complemented MiMe genotypes are described in detail herein.

[0198] As used herein, a "MiMe parent plant" generally refers to a plant that has a complete MiMe genotype, exhibits a MiMe phenotype, and is a potential source of clonal gametes (pollen and / or egg cells).

[0199] As used herein, "directly introducing a complete MiMe genotype" generally refers to introducing a genetic modification into a plant or plant cell that results in a complete MiMe genotype, and includes using the methods described herein, optionally selecting a plant or plant cell that has the complete MiMe genotype, and optionally regenerating the cell with the complete MiMe genotype into a plant that exhibits the MiMe phenotype.

[0200] As used herein, a "non-MiMe grandparent plant having a partial MiMe genotype" generally refers to a plant that has a partial MiMe genotype and exhibits a wild-type meiotic phenotype. A non-MiMe grandparent plant having a partial MiMe genotype produces haploid gametes that can be crossed with haploid gametes from the same or another non-MiMe grandparent plant having a partial MiMe genotype to produce one or more seeds that have a complete MiMe genotype and can be cultivated to produce one or more MiMe parent plants.

[0201] As used herein, "introducing a partial MiMe genotype" refers to introducing a genetic modification into a plant or plant cell that results in a partial MiMe genotype, and includes using the methods described herein, optionally selecting a plant or plant cell with a partial MiMe genotype, and regenerating the cell with the partial MiMe genotype into a plant that exhibits a wild-type meiotic phenotype. For example, introducing a partial MiMe genotype can include crossing a plant that has MiMe and non-MiMe alleles for components of sister chromatid cohesion during the first division of meiosis and MiMe and non-MiMe alleles for components of DNA double-strand breaks during meiotic recombination with a plant that has MiMe and non-MiMe alleles for components of progression during the second division of meiosis, and then selecting progeny that are heterozygous for all three parental MiMe alleles and therefore have a partial MiMe genotype.

[0202] As used herein, " genetic modification " generally refers to any sequence or part thereof in a nucleic acid molecule that is different from the sequence of an ancestor nucleic acid molecule.For example, seeds that contain inserted or removed genome sequences that do not exist in one of the parent plants contain genetic modification.Genetic modification can be naturally occurring or can be introduced.Genetic modification can be introduced, for example, by plant breeding, transgenic methods, gene editing, chemical mutagenesis, etc., to introduce the naturally occurring genetic modification of one plant lineage into another plant lineage.

[0203] As used herein, "transgenesis" refers to the insertion of an exogenous genetic element into the genome of an organism. Any exogenous genetic element can be inserted by transgenesis, including, but not limited to, genes, protein-coding sequences, non-protein-coding sequences, regulatory sequences, spacer DNA, etc.

[0204] As used herein, "gene editing" refers to a type of genetic modification in which DNA in the genome of an organism is inserted, removed, or replaced using one or more natural or engineered nucleases. Gene editing can be performed using site-specific nucleases, inducible nucleases, or a combination thereof. The nucleases create one or more site-specific breaks, such as double-strand breaks (DSBs), at target loci in the genome. Each site-specific break can be repaired, for example, by non-homologous end joining (NHEJ), which results in a genetic modification of the genome at the target locus, or by homologous recombination between the target locus and a provided repair nucleic acid molecule that contains homology to the target genome sequence and the desired genetic modification.

[0205] Polyploid seed population In one aspect, described herein is a population of polyploid seeds comprising three or more haplotypes of plants of the same or closely related species, wherein at least 50% of the population of polyploid seeds is genetically uniform, and the population was obtained from a single plant or set of plants (e.g., a set of genetically uniform plants, e.g., a set of genetically uniform F1 hybrids). In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform seeds comprise three or more haplotypes of plants of the same or closely related species. In some embodiments, the population of polyploid seeds can have complete MiMe genotypes or partial MiMe genotypes.

[0206] In another aspect, described herein is a population of polyploid seeds comprising a partially complemented MiMe genotype, wherein at least 50% of the polyploid seed population is genetically uniform, and the population was obtained from a single plant or set of plants (e.g., a set of genetically uniform plants, e.g., a set of genetically uniform F1 hybrids). In some embodiments, the polyploid seed population comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform seeds comprise a partially complemented MiMe genotype. In some embodiments, the polyploid seed population comprising a partially complemented MiMe genotype can comprise one, two, three, or more haplotypes.

[0207] Haplotype In some embodiments, the polyploid seed population or genetically uniform polyploid seed subpopulation comprises one, two, three, or more haplotypes. In some variations, the polyploid seed population or genetically uniform polyploid seed subpopulation comprises two or more haplotypes, three or more haplotypes, four or more haplotypes, five or more haplotypes, six or more haplotypes, seven or more haplotypes, or eight or more haplotypes. In additional variations, the polyploid seed population or genetically uniform polyploid seed subpopulation comprises two, three, four, five, six, seven, or eight haplotypes. In some embodiments, where the polyploid seeds are derived from an allopolyploid plant having multiple subgenomes, the two, three, or more haplotypes are two, three, or more haplotypes of the same subgenome.

[0208] plant seeds The polyploid seed population can be of any type of plant. In some embodiments, the polyploid seed population is a monocotyledonous plant seed. In other embodiments, the polyploid seed population is a dicotyledonous plant seed. In some embodiments, the polyploid seed population is a crop plant seed. In some variations, the polyploid seed population is a variety of plant, including, but not limited to, potato, corn, banana, blueberry, blackberry, watermelon, cantaloupe, tomato, tomatillo, pepper, eggplant, grape, orange, lemon, lime, grapefruit, cucumber, squash, gourd, pumpkin, apple, pear, kiwi, pomegranate, mango, guava, papaya, avocado, stone fruit, date palm, fig, alfalfa, tobacco, cotton, clover, fig, fig. Goats, currants, cranberries, gooseberries, boysenberries, raspberries, bilberries, lingonberries, cowberries, huckleberries, dewberries, caneberries, loganberries, marionberries, tayberries, plantains, red bananas, ratundan bananas, Cavendish bananas, artichokes, beets, potatoes, sweet potatoes, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yams, radishes, sesame Wasabi, turnip, parsnip, rutabaga, yucca, onion, shallot, leek, radish, garlic, chives, peanuts, asparagus, sugarcane, cassava, Brussels sprouts, cabbage, collard greens, kale, lettuce, Swiss chard, spinach, bok choy, okra, cashew nuts, pineapple, celery, birch, rapeseed, mustard greens, tea, hemp, safflower seeds, cedar, quinoa, chickpeas, citron, Satsuma mandarin, tangerine, and mandarin , clementines, coffee, cola, hazelnuts, saffron, melons and cantaloupes, carrots, oil palm, teff, rubber rabbit brush, eucalyptus, fir, soybeans, sunflowers, hemlock trees, rubber trees, kenaf, hops, walnuts, larch, lentils, flax, maple, miscanthus, basil, olives, millet, shepherd's purse, avocados, green beans, kidney beans, ground cherries, pine, pistachio nuts, peas, turfgrass, poplar, apricots, plums and prunes,The plant may be any crop plant, including almonds, nectarines, peaches, cherries, roses, raspberries, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, broad beans, cowpeas, ginger, kohlrabi, broccoli, cauliflower, wheat, rice, barley, oats, rye, bamboo, ryegrass, turfgrass, or ornamental grass. Additional variations include, but are not limited to, Solanum spp., Solanum chacoense, Solanum tuberosum, Solanum lycopersicum, Solanum melongena, Zea spp., e.g., Z. diploperennis, Z. luxurians, Z. nicaraguensis, and Z. perennis, Zea mays, e.g., Z. mays spp. mays (modern maize), Z. mays spp. Parviglumis, and Z. mays spp. mexicana, Musa spp., Musa acuminata, Musa balbisiana, Vaccinium spp., Vaccinium darrowii, Vaccinium corymbosum, Vaccinium erythrocarpum, Vaccinium macrocarpon, Vaccinium microcarpum, Vaccinium oxycoccos, Rubus spp., Rubus fruticosus, Rubus idaeus, Rubus fruticosus, Rubus aboriginum, Rubus x loganobaccus, Rubus idaeus and Rubus strigosus Rubus occidentalis, Citrullus spp., Citrullus lanatus, Cucumis spp., Cucumis melo, Physalis spp., Physalis philadelphica, Physalis ixocarpa, Capsicum spp., Capsicum annuum, Capsicum baccatum, Capsicum chinense, Capsicum frutescens, Capsicum pubescens,Vitis spp., Vitis vinifera, Vitis amurensis, Vitis labrusca, Vitis riparia, Vitis rotundifolia, Citrus spp., Citrus sinensis, Citrus reticulata, Citrus aurantium, Citrus bergamia, Citrus limon, Citrus medica, Citrus maxima, Citrus hystrix, Citrus aurantiifolia, Citrus x sinensis, Citrus x paradisi, Cucumis spp., Cucumis sativus, Cucurbita spp., Cucurbita argyrosperma, Cucurbita ficifolia, Cucurbita maxima, Cucurbita moschata, C.pepo, Lagenaria spp., Malus spp., Malus domestica, Pyrus spp., Pyrus communis, Pyrus pyrifolia, Pyrus sinkiangensis, Pyrus pashia, Actinidia spp., Actinidia deliciosa, Punica spp., Punica granatum, Mangifera spp., Mangifera indica, Mangifera foetida, Psidium spp., Psidium guajava, Carica spp., Carica papaya, Persea spp., Persea americana, Prunus spp., Phoenix spp., Phoenix dactylifera, Ficus spp., Ficus carica, Medicago spp., Medicago sativa, Nicotiana spp., Nicotiana tabacum, Nicotiana rustica, Gossypium spp., Gossypium hirsutum, Gossypium barbadense, Gossypium arboretum, Gossypium herbaceum, Trifolium spp.,Trifolium repens, Trifolium pretense, Fragaria spp., Fragaria virginiana Fragaria chiloensis, Fragaria vesca, Fragaria x ananassa, Ribes spp., Cynara spp., Cynara cardunculus, Beta spp., Beta vulgaris, Beta vulgaris subsp.vulgaris, Ipomoea spp., Ipomoea batatas, Canna spp., Canna indica, Pachyrhizus spp., Pachyrhizus ahipa, Arracacia spp., Arracacia xanthorrhiza, Lepidium spp., Lepidium meyenii, Mirabilis spp., Mirabilis expansa, Oxalis spp., Oxalis tuberosa, Ullucus spp., Ullucus tuberosus, Smallanthus spp., Smallanthus sonchifolius, Dioscorea spp., Dioscorea rotundata, Dioscorea cayennensis, Dioscorea alata, Dioscorea polystachya, Dioscorea bulbifera, Dioscorea esculenta, Dioscorea dumetorum, Dioscorea trifida, Raphanus spp.Raphanus raphanistrum, Armoracia spp., Armoracia rusticana, Brassica spp., Brassica rapa, Brassica rapa subsp.chinensis, Brassica napus, Brassica oleracea, Brassica oleracea, Brassica oleracea var.oleracea, Brassica oleracea var.italica, Pastinaca spp., Pastinaca sativa, Yucca spp., Allium spp., Allium cepa,The polyploid seed population can be of any species of crop plant, including Allium ampeloprasum, Allium chinense, Allium fistulosum, Allium x proliferum, Allium sativum, Allium schoenoprasum, Arachis spp., Arachis hypogaea, Asparagus spp., Asparagus officinalis, Saccharum spp., Saccharum officinarum, Saccharum barberi, Saccharum robustum, Saccharum spontaneum, Manihot spp., Manihot esculenta, Lactuca spp., Lactuca sativa, Spinacia spp., and Spinacia oleracea.

[0209] In some embodiments, the polyploid seed population is from an Arabidopsis plant. In certain embodiments, the polyploid seed population is from an Arabidopsis thaliana plant. In some embodiments, the polyploid seed population is from the hybrid of two Arabidopsis thaliana plants that are from two or more lines of Arabidopsis thaliana. In certain embodiments, the two or more lines of Arabidopsis thaliana include Col-0, Landsberg, Shahdara, HR-10, Ws-2, Col-0(CS851557-S1), CS851294, Col x Shahdara F1, Landsberg x Shahdara F1, Col x Shahdara F2, Landsberg x Shahdara F2, Col-0(CS851557-S1) x HR-10 F2, Col-0 x HR-10 F2, Shahdara x Ws-2 F2, or a combination thereof.

[0210] In some embodiments, the polyploid seed population comprises two, three, or more haplotypes of plants of the same species or closely related species. In another embodiment, the polyploid seed population comprises two, three, or more haplotypes of plants of closely related species. In some embodiments, closely related plants are plants of species within the same family. In other embodiments, closely related plants are plants of species within the same genus.

[0211] In some embodiments, the polyploid seed population is a population of seeds from the family Solanaceae, comprising two, three, or more haplotypes from one or more species within the family Solanaceae. In some embodiments, the polyploid seed population is a population of seeds from the genus Solanum, comprising two, three, or more haplotypes from one or more species within the genus Solanum. The polyploid seed population of the genus Solanum can be a population of seeds from any plant within the genus Solanum, including, but not limited to, potato, tomato, and eggplant. In some variations, the two, three, or more haplotypes can be from any species or subspecies within the genus Solanum, including, but not limited to, Solanum chacoense, Solanum tuberosum, Solanum tuberosum ssp. andigena, Solanum tuberosum ssp. tuberosum, Solanum lycopersicum, Solanum pimpinellifolium, Solanum peruvianum, Solanum cheesmanii, Solanum galapagense, Solanum chilense, Solanum aethiopicum, Solanum quitoense, Solanum torvum, Solanum muricatum, Solanum betaceum, Solanum lycocarpum, Solanum scabrum, and Solanum spp. In certain embodiments, the population of polyploid seeds is a population of potato seeds that includes two, three, or more haplotypes from the same or closely related species of potato.In some variations, the population of potato seeds comprises two, three, or more haplotypes of potato species or subspecies, including, but not limited to, Solanum chacoense, Solanum tuberosum, Solanum tuberosum ssp. andigena, Solanum tuberosum ssp. tuberosum, Solanum stenotomum, Solanum phureja, Solanum goniocalyx, Solanum ajanhuiri, Solanum chaucha, Solanum juzepczukii, Solanum curtilobum, Solanum brevicaule, Solanum fendleri, Solanum demissum, and Solanum bulbocastanum.

[0212] In some embodiments, the population of polyploid seeds includes two, three, or more haplotypes of potato. In some variations, the two, three, or more haplotypes may be derived from different subspecies of Solanum tuberosum, such as, but not limited to, Solanum tuberosum ssp. andigena, Solanum tuberosum ssp. Tuberosum, related Solanum species, such as, but not limited to, Solanum chacoense, or Solanum tuberosum with introgression from a related Solanum species, such as, but not limited to, Solanum microdontum, Solanum berthaultii, Solanum tarijense, Solanum raphanifolium, Solanum verrucosum, etc.

[0213] In some embodiments, the polyploid seed population is a population of seeds of the family Ericaceae, comprising two, three, or more haplotypes from one or more species within the family Ericaceae. In some embodiments, the polyploid seed population is a population of seeds of the genus Vaccinium, comprising two, three, or more haplotypes from one or more species within the genus Vaccinium. The polyploid seed population of the genus Vaccinium can be a population of seeds of any plant within the genus Vaccinium, including, but not limited to, blueberries, cranberries, bilberries, lingonberries, cowberries, and huckleberries.In some variations, two, three, or more haplotypes may include, but are not limited to, Vaccinium darrowii, Vaccinium corymbosum, Vaccinium boreale, Vaccinium caesariense, Vaccinium caespitosum, Vaccinium elliottii, Vaccinium cereum, Vaccinium myrsinites, Vaccinium myrtilloides, Vaccinium macrocarpon, Vaccinium oxycoccos, Vaccinium microcarpum, Vaccinium erythrocarpum, Vaccinium ovatum, Vaccinium uliginosum, Vaccinium vitis-idaea, Vaccinium stamineum, Vaccinium caesium, Vaccinium calycinum, Vaccinium cespitosum, Vaccinium deliciosum, Vaccinium dentatum, Vaccinium membranaceum, Vaccinium myrtillus, Vaccinium ovalifolium, Vaccinium parvifolium, Vaccinium praestans, Vaccinium reticulatum, Vaccinium scoparium, Vaccinium koreanum, Vaccinium angustifolium, Vaccinium stenophyllum、Vaccinium fuscatum、Vaccinium atrococcum、Vaccinium pallidum、Vaccinium vacillans、Vaccinium tenellum、Vaccinium virgatum、Vaccinium ashei、Vaccinium moupinense、Vaccinium arboretum、Vaccinium crassifolium、Vaccinium spp.In certain embodiments, the population of polyploid seeds is a population of blueberry seeds that includes two, three, or more haplotypes from the same or closely related species of blueberry. In some variations, the population of blueberry seeds comprises two, three, or more haplotypes of a blueberry species or subspecies, including, but not limited to, Vaccinium darrowii, Vaccinium corymbosum, Vaccinium angustifolium, Vaccinium boreale, Vaccinium caesariense, Vaccinium corymbosum, Vaccinium darrowii, Vaccinium elliottii, Vaccinium formosum, Vaccinium fuscatum, Vaccinium atrococcum, Vaccinium hirsutum, Vaccinium myrsinites, Vaccinium myrtilloides, Vaccinium pallidum, Vaccinium simulatum, Vaccinium tenellum, Vaccinium virgatum, and Vaccinium ashei.

[0214] In some embodiments, the polyploid seed population is a population of seeds from the family Rosaceae, comprising two, three, or more haplotypes from one or more species within the family Rosaceae. In some embodiments, the polyploid seed population is a population of seeds from the genus Rubus, comprising two, three, or more haplotypes from one or more species within the genus Rubus. The polyploid seed population of Rubus can be a population of seeds from any plant within the genus Rubus, including, but not limited to, blackberry, raspberry, dewberry, caneberry, loganberry, boysenberry, marionberry, and tayberry. In some variations, two, three, or more haplotypes may be present in a variety of species, including, but not limited to, Rubus fruticosus, Rubus aboriginum, Rubus allegheniensis, Rubus arcticus, Rubus arizonensis, Rubus armeniacus, Rubus caesius, Rubus canadensis, Rubus chamaemorus, Rubus coreanus, Rubus cuneifolius, Rubus depavitus, Rubus flagellaris, Rubus geoides, Rubus glaucifolius, Rubus hispidus, Rubus hochstetterorum, Rubus idaeus, Rubus invisus, Rubus laciniatus, Rubus lasiococcus, Rubus leucodermis, Rubus occidentalis, Rubus odoratus, Rubus parviflorus, Rubus parvifolius, Rubus pectinellus, Rubus pensilvanicus, Rubus phoenicolasius, Rubus The plant may be from any species or subspecies within the genus Rubus, including Rubus pubescens, Rubus reflexus, Rubus saxatilis, Rubus spectabilis, Rubus strigosus, Rubus trifidus, Rubus ursinus, and Rubus spp.In certain embodiments, the population of polyploid seeds is a population of blackberry seeds that includes two, three, or more haplotypes from the same or closely related species of blackberry. In some variations, the population of blackberry seeds includes two, three, or more haplotypes from blackberry species or subspecies, including, but not limited to, Rubus fruticosus, Rubus plicatus, Rubus armeniacus, Rubus laciniatus, Rubus occidentalis, Rubus allegheniensis, Rubus canadensis, Rubus cuneifolius, Rubus hochstetterorum, Rubus leucodermis, Rubus odoratus, Rubus pensilvanicus, Rubus pubescens, Rubus trifidus, and Rubus ursinus.

[0215] In some embodiments, the polyploid seed population is a population of seeds from the Poaceae family, comprising two, three, or more haplotypes from one or more species within the Poaceae family. The polyploid seed population of the Poaceae family can be a population of seeds from any plant within the Poaceae family, including, but not limited to, maize, wheat, rice, barley, millet, sugarcane, oats, rye, bamboo, ryegrass, turfgrass, ornamental grasses, etc. In some embodiments, the polyploid seed population comprises two, three, or more haplotypes of maize. In some variations, the two, three, or more haplotypes can be from different maize subspecies. In some embodiments, the polyploid seed population is a population of seeds from the genus Zea, comprising two, three, or more haplotypes from one or more species within the genus Zea. The polyploid seed population of Zea can be a seed population of any plant within the genus Zea, including, but not limited to, maize and teosinte. In some variations, the two, three, or more haplotypes can be from any species or subspecies within the genus Zea, including, but not limited to, Zea mays, Zea diploperennis, Zea nicaraguensis, Zea perennis, and Zea spp. In certain embodiments, the polyploid seed population is a maize seed population containing two, three, or more haplotypes from the same or closely related species of maize or teosinte, including, but not limited to, the Zea species described herein.

[0216] In some embodiments, the polyploid seed population is a population of seeds from the family Musaceae, comprising two, three, or more haplotypes from one or more species within the family Musaceae. In some embodiments, the polyploid seed population is a population of seeds from the genus Musa, comprising two, three, or more haplotypes from one or more species within the genus Musa. The polyploid seed population of Musa can be a population of seeds from any plant within the genus Musa, including, but not limited to, banana, plantain, red banana, rattan banana, and Cavendish banana. In some variations, the two, three, or more haplotypes can be from any species or subspecies within the genus Musa, including, but not limited to, Musa acuminata, Musa acuminata subsp. zebrine, Musa balbisiana, Musa basjoo, Musa velutina, Musa yunnanensis, Musa coccinea, Musa schizocarpa, Musa x troglodytarum, Musa x paradisiaca, and Musa spp. In certain embodiments, the population of polyploid seeds is a population of banana or plantain seeds that includes two, three, or more haplotypes from the same or closely related species of banana or plantain, including, but not limited to, the Musa species described herein.

[0217] Genetic uniformity, polyploidy, and origin In some embodiments, at least 50% of a population of polyploid seeds comprising two, three, or more haplotypes are genetically homogeneous. In some variations, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.9%, or at least 99.99% of a population of polyploid seeds comprising two, three, or more haplotypes are genetically homogeneous. In some embodiments, at least 50% of the population of polyploid seeds produced is genetically homogeneous, wherein the polyploid seeds comprise three or more haplotypes. In some variations, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.9%, or at least 99.99% of the population of polyploid seeds produced is genetically homogeneous, wherein the polyploid seeds comprise three or more haplotypes. In some embodiments, the population of polyploid seeds has an average pairwise genetic homogeneity of at least 80%, as measured by the Jaccard similarity coefficient. In some variations, the population of polyploid seeds has an average pairwise genetic uniformity of at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity index. In one variation, the population of polyploid seeds has an average pairwise genetic uniformity of at least 85%, as measured by the Jaccard similarity index. In another variation, the population of polyploid seeds has an average pairwise identity of at least 90%, as measured by the Jaccard similarity index.

[0218] In some embodiments, the population of polyploid seeds comprises a subpopulation of genetically homogeneous polyploid seeds at an amount of at least 50% of the total number of seeds. In some variations, the population of polyploid seeds comprises a subpopulation of genetically homogeneous polyploid seeds at an amount of at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.9%, or at least 99.99% of the total number of seeds. In some embodiments, each pair of the subpopulation of genetically homogeneous seeds has a pairwise identity of at least about 90%, as measured by the Jaccard similarity coefficient. In some embodiments, each pair of the genetically homogeneous seed subpopulations has a pairwise identity of at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100% as measured by the Jaccard similarity index.

[0219] In some embodiments, the population of polyploid seeds or the subpopulation of genetically uniform polyploid seeds comprising two, three, or more haplotypes is triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid. In other embodiments, the population of polyploid seeds or the subpopulation of genetically uniform polyploid seeds comprising two, three, or more haplotypes has a ploidy of 9n, 10n, 11n, 12n, 13n, 14n, 15n, 16n, or higher.

[0220] In some embodiments, the polyploid seed population is obtained from a single plant or a set of plants, such as a set of F1 hybrids. In some embodiments, the polyploid seed population is obtained from a single plant. In other embodiments, the polyploid seed population is obtained from a set of F1 hybrids. In some variations, the polyploid seed population is obtained from a set of two, three, four, five, 10, 20, 50, 100, or more F1 hybrids. In some additional variations, the polyploid seed population is obtained from a set of genetically uniform plants, such as a set of F1 hybrids derived from the same inbred parent. In yet further variations, the polyploid seed population is obtained from a set of two, three, four, five, 10, 20, 50, 100, or more genetically uniform plants, such as a set of genetically uniform F1 hybrids. In certain embodiments, a set of genetically homogeneous plants (e.g., a set of genetically homogeneous F1 hybrids) has a mean pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity index. In certain embodiments, each pair of genetically homogeneous plants (e.g., a set of genetically homogeneous F1 hybrids) has a pairwise identity of at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or 100%, as measured by the Jaccard similarity index.

[0221] Methods for measuring genetic uniformity are known in the art.One exemplary method for measuring genetic uniformity is by using the Jaccard similarity coefficient, also known as the Jaccard index or Jaccard similarity index.In the context of molecular plant genetics, the Jaccard index, Jaccard similarity index, or Jaccard similarity coefficient (Jaccard, P. (1908) Nouvelles Recherches sur la Distribution Florale.Bulletin de la Societe Vaudoise des Sciences Naturelles.Vol.44) is generally applied to quantify the pairwise genetic similarity or uniformity of plants based on the presence or absence of shared alleles at loci distributed throughout the genome. An exemplary method of using the Jaccard similarity index to measure genetic uniformity between two plants is described in Example 1 below, as well as in, for example, Paz and S. V. Beilleux (1997. Genetic diversity based on randomly amplified polymorphic DNA (RAPD) and its relationship with the performance of diploid potato hybrids. Journal of the American Society for Horticultural Sci. 122(6):740-747), Vosman et al. (2004.The establishment of 'essential derivation' among rose varieties, using AFLP.Theoretical and Applied Genetics.109:1718-1725), Noli et al. (2013.Criteria for the definition of similarity thresholds for identifying essentially derived varieties.Plant Breeding.132(6):525-531), Vijayakumar et al. (2021.High temperature It is described in induced changes in quality and yield parameters of tomato(Solanum lycopersicum L.) and similarity coefficients among genotypes using SSR markers.Heliyon.7(2)) and Dalamu et al. (2023.Genetic Diversity and Population Structure Analyses Using Simple Sequence Repeat Markers and Phenotypic Traits in Native Potato Collection in India.Potato Research:1-25). The Jaccard similarity coefficient is defined as the ratio of the number of shared items to the total number of different items in the two sets. In the context of molecular plant genetics, this quantifies the proportion of alleles shared between two plants. The formula for calculating the Jaccard similarity coefficient is: J(A,B)=|A∩B| / |A∪B|

[0222] In the formula, A represents the set of unique, non-overlapping alleles in one plant, B represents the set of unique, non-overlapping alleles in the other plant, |A∩B| represents the number of shared alleles between the plants (the common set concentration), and |A∪B| represents the number of different alleles between the plants (the union concentration). This formula calculates the common set concentration (shared alleles) of two sets divided by the union concentration (all alleles) of the two sets (all different alleles present). The resulting Jaccard similarity coefficient ranges from 0 to 1, where 0 indicates no shared alleles and 1 indicates complete homogeneity. The mean pairwise genetic homogeneity of a population was calculated as the mean Jaccard similarity of all possible pairs of plants within the population. In the context of pairwise genetic similarity assessment, the size of A should be the same as or very close to the size of B to avoid misinterpretation. Genetic modification

[0223] In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) contain one or more genetic modifications. Genetic modifications can be made by modifying any nucleic acid sequence or genetic element by inserting, deleting, or substituting one or more nucleotides in a nucleic acid molecule. This can be achieved by substituting at least one nucleotide, deleting at least one nucleotide, inserting at least one nucleotide, chemically modifying at least one nucleotide, or a combination thereof, as long as the result is a detectable change in the nucleotide sequence compared to the sequence of the nucleic acid molecule before modification (e.g., by PCR, DNA sequencing, chromatography, etc.). Such modifications can be achieved by any of several well-known methods known in the art, including, but not limited to, random mutagenesis, genome editing, inserting recombinant nucleic acids, crossing an unmodified plant with a modified plant and introducing the modifications of the modified plant into the unmodified plant, etc. Genetic modifications can be naturally occurring or non-natural.

[0224] The genetic modifications described herein may be present in any known genetic element, including, but not limited to, protein-coding sequences, non-protein-coding sequences, promoter regions, 5' untranslated leaders, genes, exons, introns, polyA signal sequences, 3' untranslated regions, regions encoding small RNAs (e.g., microRNAs and small interfering RNAs), and any other sequences that affect the transcription or translation of one or more nucleic acid sequences. In some embodiments, the genetic modification may include, but is not limited to, modification or replacement of a nucleotide sequence of interest (e.g., a regulatory element), gene disruption, gene knockout, gene knockdown, gene knock-in, gene silencing (e.g., by expressing an inverted repeat in a gene of interest), RNA interference (e.g., by inserting and / or expressing an RNA interference construct), modification of methylation status, modification of a splicing site, introduction of an alternative splicing site, or any combination thereof. As used herein, a genetic disruption that results in a decrease in expression (including non-expression or altered activity) of a functional protein gene product refers to a change in sequence or insertion of a sequence into a gene or locus. Gene disruption can be achieved by introducing genetic modification of protein-coding sequence, for example, but not limited to, missense or nonsense mutation, or insertion, deletion or substitution.As used herein, knockout is the genetic modification that gene or gene product is completely disabled.Knockout of gene product can be achieved by introducing genetic modification into the protein-coding sequence of gene described herein or any non-protein-coding sequence or regulatory sequence.As used herein, knockdown is the genetic modification that gene or gene product is partially disabled.Knockdown of a gene product can be achieved by introducing genetic modifications into the protein-coding or non-protein-coding sequence or regulatory sequence of a gene, or by inserting a trans-acting element, such as a construct expressing an inverted repeat of the gene product or a construct expressing a DNA or RNA binding protein, such as a transcriptional repressor, which can include, for example, an inactivated targeted nuclease, such as inactivated Cas9 (dCas9). As used herein, knock-in refers to the replacement or insertion of a DNA sequence at a specific DNA locus in a cell. Knock-in can include, but is not limited to, the specific insertion of a heterologous amino acid coding sequence into the coding region of a gene, the insertion of a transcriptional regulatory element into the locus, or any of several methods known to those skilled in the art for inserting a DNA sequence into a cell.

[0225] In certain embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression (including non-expression or altered activity) of a gene product at a genomic locus. In some embodiments, genetic modifications that result in reduced expression (including non-expression or altered activity) of a gene product or locus may include, but are not limited to, modifications of enhancers, promoters, 5' untranslated leaders, coding regions, non-coding regions, insertion and / or expression of RNA interference constructs targeting mRNA, modifications of regions encoding small RNAs, modifications of the methylation status of genomic loci, expression of repressor proteins targeting DNA or mRNA sequences, and any other sequences that affect the transcription or translation of one or more nucleic acid sequences. In some embodiments, genetic modifications that result in reduced expression (including non-expression or altered activity) of a gene product or locus include, but are not limited to, modification or substitution of a nucleotide sequence of interest (e.g., a regulatory element), gene disruption, gene knockout, gene knockdown, gene knock-in, gene silencing (e.g., by inserting and / or expressing an inverted repeat into a gene of interest), RNA interference (e.g., by inserting and / or expressing an RNA interference construct), expression of a repressor protein (e.g., dCas9), modification of the methylation status of a locus, modification of a splicing site, introduction of an alternative splicing site, or any combination thereof. In some variations, the genetic modification is located after the first 70%, first 60%, first 50%, first 40%, first 30%, first 20%, or first 10% of nucleotides in the 3' direction of the start codon of the coding sequence of the genomic locus. In certain variations, the genetic modifications are located after the first 100, first 200, first 300, first 400, first 500, first 600, first 700, first 800, first 900, first 1000, first 1250, first 1500, first 1750, first 2000, first 2500, or first 3000 nucleotides 3' of the start codon of the coding sequence of the genomic locus.

[0226] In some embodiments, the one or more genetic modifications each independently comprise an insertion, deletion, one or more nucleotide changes, or inversion that results in reduced expression of one or more genomic loci (e.g., MiMe loci). In some variations, the insertion, deletion, one or more nucleotide changes, or inversion eliminates expression (e.g., eliminates activity) of the genomic locus. In some variations, the insertion, deletion, one or more nucleotide changes, or inversion is located after the first 70%, first 60%, first 50%, first 40%, first 30%, first 20%, or first 10% of nucleotides in the 3' direction of the start codon of the coding sequence of the genomic locus. In certain variations, the insertion, deletion, one or more nucleotide changes, or inversion are located after the first 100, first 200, first 300, first 400, first 500, first 600, first 700, first 800, first 900, first 1000, first 1250, first 1500, first 1750, first 2000, first 2500, or first 3000 nucleotides 3' of the start codon of the coding sequence of the genomic locus. In some embodiments, the insertion, deletion, one or more nucleotide changes, or inversion eliminate expression (e.g., eliminate activity) of the genomic locus. In some variations, the insertion, deletion, one or more nucleotide changes, or inversion results in a premature stop codon being present after the first 70%, first 60%, first 50%, first 40%, first 30%, first 20%, or first 10% of nucleotides 3' of the start codon of the coding sequence of the MiMe locus, thereby eliminating expression (e.g., activity) of the genomic locus. In some variations, the insertion, deletion, one or more nucleotide changes, or inversion results in a premature stop codon being present after the first 100, first 200, first 300, first 400, first 500, first 600, first 700, first 800, first 900, first 1000, first 1250, first 1500, first 1750, first 2000, first 2500, or first 3000 nucleotides 3' of the coding sequence of the genomic locus, thereby eliminating expression (e.g., activity) of the genomic locus.

[0227] In some embodiments, the one or more genetic modifications comprise one or more polynucleotide sequences selected from the group consisting of SEQ ID NOs: 448-466, 468-471, 474-491, and 493-496. In certain embodiments, the one or more genetic modifications comprise one or more polynucleotide sequences each having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity or complementarity to a nucleotide sequence selected from the group consisting of SEQ ID NOs: 448-466, 468-471, 474-491, and 493-496.

[0228] MiMe loci, MiMe genotypes, and MiMe components In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) contain one or more genetic modifications that result in reduced expression (including non-expression or altered activity) of one or more MiMe loci. In some variations, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) contain one or more genetic modifications that result in a reduced amount of a functional gene product encoded by one or more MiMe loci. Gene products of MiMe loci may include, but are not limited to, nucleic acids (e.g., RNA), post-transcriptionally modified nucleic acids (e.g., spliced ​​RNA, polyadenylated mRNA), proteins (e.g., enzymes, structural proteins, etc.), and post-translationally modified proteins (e.g., glycoproteins, lipoproteins, etc.). The function of a gene product of a MiMe locus refers to the unmodified wild-type function of the gene product. A reduction in expression of a MiMe locus can refer to a reduction in the total amount of gene product encoded by the MiMe locus present in a cell (e.g., a reduction in the amount of protein, including a reduction to the point where expression is no longer detectable) or a reduction in the amount of a functional gene product encoded by the MiMe locus present in a cell (e.g., a reduction in the percentage of protein with wild-type function, or an increase in the percentage of protein with altered activity). In some embodiments, one or more genetic modifications that result in reduced expression of one or more MiMe loci can include, but are not limited to, modifications of an enhancer at the MiMe locus, modifications of a promoter at the MiMe locus, modifications of a coding region at the MiMe locus, modifications of the methylation status of the MiMe locus, expression of a repressor protein that targets DNA or mRNA at the MiMe locus, and expression of an RNA interference construct that targets mRNA from the MiMe locus. In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) can contain one or more genetic modifications that result in the non-expression of one or more MiMe loci. In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) may contain one or more genetic modifications that result in reduced expression (including non-expression or altered activity) of a combination of two or more MiMe loci.

[0229] In some embodiments, the polyploid seeds comprise one or more genetic modifications that result in reduced expression of one or more MiMe loci. In other embodiments, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of two or more MiMe loci. In yet other embodiments, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of three or more MiMe loci. In some variations, MiMe loci may include, but are not limited to, REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, PS1-like protein, JASON (e.g., JASON-1 and / or JASON-2 in maize), PC1, PC2, and FC. In one variation, the polyploid seed (e.g., a subpopulation of genetically uniform polyploid seeds) comprises one or more genetic modifications that result in reduced expression of REC8. In a second variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize). In a third variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In a fourth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of SPO11-1, SPO11-2, or a combination thereof. In a fifth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8 and SPO11-1.In a sixth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8 and OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize). In a seventh variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8 and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In an eighth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize) and SPO11-1. In a ninth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize) and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In a tenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In an eleventh variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), and SPO11-1. In a twelfth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of PS1 and SPO11-1. In a thirteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of PS1 and SY3.In a fourteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are corn seeds and comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in corn), SPO11-1, and REC8. In a fifteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are potato seeds and comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SPO11-1. In a sixteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are potato seeds and comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SY3. In a seventeenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are potato seeds and comprise one or more genetic modifications that result in altered activity of TDM1 (e.g., a dominant-negative, constitutively active, or null mutant of TDM1). In an eighteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are potato seeds and comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SPO11-1. In a nineteenth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) are potato seeds and comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SY3. In a twentieth variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), SPO11-1, and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In a twenty-first variation, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of PS1 or a PS1-like protein, SY3, and SPO11-1. The polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) may comprise one or more genetic modifications that result in reduced expression of any combination of MiMe loci described herein or known in the art.In some embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) may comprise one or more genetic modifications that result in the non-expression of any combination of MiMe loci described herein or known in the art. In further embodiments, polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) may comprise one or more genetic modifications that result in the reduced expression (including non-expression or altered activity) of a combination of two or more MiMe loci described herein or known in the art.

[0230] In some embodiments, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof. In some variations, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof, and one or more genetic modifications that result in reduced expression of one or more additional MiMe loci. In further variations, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof, and one or more genetic modifications that result in reduced expression of one or more additional MiMe loci, which may include, but are not limited to, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PC1, PC2, and FC. In further variations, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of REC8, SWITCH1 / DYAD, or a combination thereof, one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PC1, PC2, FC, or any combination thereof, and one or more genetic modifications that result in reduced expression of one or more additional MiMe loci, which may include, but are not limited to, PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, and SY4.

[0231] In some embodiments, the polyploid seed (e.g., a subpopulation of genetically uniform polyploid seed) comprises one or more genetic modifications that result in reduced expression of one or more MiMe loci, which may include, but are not limited to, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PC1, PC2, and FC. In some variations, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PC1, PC2, FC, or any combination thereof, and further comprise one or more genetic modifications that result in reduced expression of one or more additional MiMe loci, which may include, but are not limited to, PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, and SY4.

[0232] In some embodiments, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of one or more MiMe loci, which may include, but are not limited to, PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, and SY4. In some variations, the polyploid seeds (e.g., a subpopulation of genetically uniform polyploid seeds) comprise one or more genetic modifications that result in reduced expression of PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof, and further comprise one or more genetic modifications that result in reduced expression of one or more additional MiMe loci, which may include, but are not limited to, PS1, a PS1-like protein, and JASON (e.g., JASON-1 and / or JASON-2 in maize).

[0233] In some embodiments, each of the one or more MiMe loci encodes a MiMe component protein as described herein. In certain embodiments, each of the one or more MiMe loci encodes a protein having an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-119. In some variations, each of the one or more MiMe loci encodes a protein having at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 98% sequence identity or at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 98% sequence similarity to an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-119.

[0234] In some embodiments, the polyploid seed population or the genetically uniform polyploid seed subpopulation has a complete MiMe genotype. In alternative embodiments, the polyploid seed population or the genetically uniform polyploid seed subpopulation has a partial MiMe genotype. In yet other embodiments, the polyploid seed population or the genetically uniform polyploid seed subpopulation has a partially complemented MiMe genotype. In certain embodiments, the complete MiMe genotype, the partial MiMe genotype, or the partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of one or more MiMe loci. In other embodiments, the complete MiMe genotype, the partial MiMe genotype, or the partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of two or more MiMe loci. In yet other embodiments, the complete MiMe genotype, the partial MiMe genotype, or the partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of three or more MiMe loci. In some variations, MiMe loci may include, but are not limited to, REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), CYCA1, TDM1, PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize), SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, SWITCH1 / DYAD, PS1, PS1-like protein, JASON (e.g., JASON-1 and / or JASON-2 in maize), PC1, PC2, and FC. In one variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8. In a second variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype includes one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize).In a third variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In a fourth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of SPO11-1, SPO11-2, or a combination thereof. In a fifth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8 and SPO11-1. In a sixth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8 and OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize). In a seventh variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8 and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In an eighth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize) and SPO11-1. In a ninth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize) and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize).In a tenth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), and PAIR1 (e.g., PAIR1-1 and / or PAIR1-2 in maize). In an eleventh variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maize), and SPO11-1. In a twelfth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of PS1 and SPO11-1. In a thirteenth variation, the complete, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in reduced expression of PS1 and SY3. In a fourteenth variation, the population of polyploid seeds is corn seeds, and the complete, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in reduced expression of OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3), SPO11-1, and REC8. In a fifteenth variation, the population of polyploid seeds is potato seeds, and the complete, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SPO11-1. In a sixteenth variant, the population of polyploid seeds is potato seeds, and the full MiMe genotype, partial MiMe genotype, and partially complemented MiMe genotype comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SY3.In a seventeenth variation, the population of polyploid seeds are potato seeds, and the full, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in altered activity of TDM1 (e.g., TDM1 dominant-negative, constitutively active, or null mutants). In an eighteenth variation, the polyploid seeds are potato seeds, and the full, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SPO11-1. In a nineteenth variation, the polyploid seeds are potato seeds, and the full, partial, and partially complemented MiMe genotypes comprise one or more genetic modifications that result in reduced expression of a PS1-like protein and SY3. In a twentieth variation, the complete MiMe genotype, partial MiMe genotype, or partially complemented MiMe genotype comprises one or more genetic modifications that result in reduced expression of REC8, OSD1 (e.g., OSD1-1, OSD1-2, and / or OSD1-3 in maiz...

Claims

1. A population of polyploid seeds comprising a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, wherein the genetically uniform polyploid seeds comprise three or more haplotypes of plants of the same or closely related species, and the population is obtained from a single plant or a set of F1 hybrids.

2. 2. The population of claim 1, wherein the subpopulation of genetically uniform polyploid seeds is triploid, tetraploid, pentaploid, hexaploid, 7ploid, or octaploid.

3. 2. The population of claim 1, wherein the population of polyploid seeds has an average pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, as measured by the Jaccard similarity index.

4. 2. The population of claim 1, wherein the population of polyploid seeds comprises the genetically uniform subpopulation of polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds.

5. 2. The population of claim 1, wherein each pair of seeds in the subpopulation of genetically uniform polyploid seeds has a pairwise identity of at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% as measured by the Jaccard similarity coefficient.

6. The subpopulation of genetically uniform polyploid seeds is (A) a MiMe allele that confers reduced expression of one or more MiMe loci of each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis; (2) a component of DNA double-strand breaks during meiotic recombination; and (3) a component of progression through the second division of meiosis, and wherein each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; or (B) A MiMe allele that confers reduced expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) a component of DNA double-strand breaks during meiotic recombination; and (4) a component of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components. The population of claim 1, having a complete MiMe genotype comprising:

7. The subpopulation of genetically uniform polyploid seeds is (A) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of the first, second, and third MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first, second, and third MiMe components, the partial MiMe genotype, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; or (B) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of said first and second MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first and second MiMe components, 2. The population of claim 1, having the partial MiMe genotype, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component.

8. The subpopulation of genetically uniform polyploid seeds is (A) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component; and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said second MiMe component; (c) a partially complemented MiMe genotype comprising either (i) only MiMe alleles at one or more MiMe loci of a third MiMe component, or (ii) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of said third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said third MiMe component, the partially complemented MiMe genotype, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component; (B) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component; and (b) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said second MiMe component, the partially complemented MiMe genotype, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) components of DNA double-strand breaks during meiotic recombination; and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component; or (C) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, wherein said first MiMe component is a component of a DNA double-strand break during meiotic recombination; (b) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a second MiMe component; and (c) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a third MiMe component; and (d) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, the partially complemented MiMe genotype, wherein the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during meiosis I, (3) a component of progression through meiosis II, and (4) a component of progression through meiosis I, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component.

2. The population of claim 1, having:

9. (1) the one or more MiMe loci of components of meiotic division I sister chromatid cohesion include REC8, SWITCH1 / DYAD, or a combination thereof; (2) the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof; (3) the one or more MiMe loci of components of progression through the second division of meiosis include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof; and / or (4) The population described in claim 6, wherein the one or more MiMe loci of components of progression through the first division of meiosis include PS1, JASON, or a combination thereof.

10. The subpopulation of genetically uniform polyploid seeds is (1) A complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic alterations that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (2) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (3) a complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (4) (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) a partial MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1, optionally wherein the population of polyploid seeds is derived from a maize plant and the one or more OSD1 loci comprise OSD1-1 and OSD1-2; (5) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (6) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (7) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (8) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (9) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (10) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (11) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (12) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (13) A complete MiMe genotype comprising: (i) an os allele, wherein a subpopulation of the genetically uniform polyploid seeds is homozygous for the os allele; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1. (14) A partial MiMe genotype comprising: (i) an os allele, wherein a subpopulation of the genetically uniform polyploid seeds is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1. (15) A complete MiMe genotype comprising (i) a ps allele, wherein a subpopulation of the genetically uniform polyploid seeds is homozygous for the ps allele, and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (16) A partial MiMe genotype comprising: (i) a ps allele, wherein a subpopulation of the genetically uniform polyploid seeds is heterozygous for the ps allele; and (ii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1. (17) (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (18) (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (19) (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic alterations that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (20) A partially complemented MiMe genotype comprising: (i) a ps allele, wherein a subpopulation of the genetically uniform polyploid seeds is heterozygous for the ps allele; (ii) an os allele, wherein a subpopulation of the genetically uniform polyploid seeds is heterozygous for the os allele; (iii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only a MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; or (21) A partially complemented MiMe genotype comprising: (i) an os allele, wherein a subpopulation of the genetically uniform polyploid seeds is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1; (iii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1.

2. The population of claim 1, comprising:

11. 2. The population of claim 1, wherein the subpopulation of genetically uniform polyploid seeds comprises one or more polynucleotide sequences selected from the group consisting of SEQ ID NOs: 448-466, 468-471, 474-491, and 493-496.

12. 2. The population of claim 1, wherein germination of seeds of said subpopulation of genetically uniform polyploid seeds results in sterile plants that produce nonviable gametes, seedless fruit, or a combination thereof.

13. The population of polyploid seeds may be selected from the group consisting of potato, corn, banana, blueberry, blackberry, watermelon, cantaloupe, tomato, tomatillo, pepper, eggplant, grape, orange, lemon, lime, grapefruit, cucumber, squash, gourd, pumpkin, apple, pear, kiwi, pomegranate, mango, guava, papaya, avocado, stone fruit, date, fig, alfalfa, tamarind, and the like. Baco, cotton, clover, strawberry, currant, cranberry, gooseberry, boysenberry, raspberry, artichoke, beet, potato, sweet potato, edible canna, ahipa, arracacha, maca, nashua, mauka, ouca, uruco, yacon, yam, radish, horseradish, turnip, parsnip, rutabaga, yucca, corn, onion, shallot, leeks Bell radish, garlic, chives, peanuts, asparagus, sugarcane, cassava, Brussels sprouts, cabbage, collard greens, kale, lettuce, Swiss chard, spinach, bok choy, okra, cashews, pineapple, celery, oats, birch, rapeseed, mustard, tea, hemp, safflower seeds, cedar, quinoa, chickpeas, citron, Satsuma mandarin, tangerine, mandarin orange Apple, clementine, coffee, cola tree, hazelnut, saffron, melon, cantaloupe, carrot, oil palm, teff, rubber rabbitbrush, eucalyptus, fir, soybean, sunflower, hemlock tree, rubber tree, kenaf, barley, hops, walnut, larch, lentil, flax, ryegrass, maple, silver grass, basil, olive, rice, millet, shepherd's purse, green beans, kidney beans, nightshade, pine , pistachio nuts, peas, turfgrass, poplar, apricot, plum, prune, almond, nectarine, peach, cherry, rose, bramble, rye, sesame, sorghum, spruce, switchgrass, Russian dandelion, cocoa, durum wheat, spelt, wheat, fava beans, cowpeas, ginger, kohlrabi, broccoli, and cauliflower.

14. 10. A method for producing a population of polyploid seeds according to claim 1, comprising: (a) creating a first MiMe parent plant and a second MiMe parent plant by introducing genetic modifications into one or more candidate lines to generate MiMe alleles in the germplasm of a first MiMe parent plant, a second MiMe parent plant, and / or its ancestors, wherein the first MiMe parent plant and the second MiMe parent plant each comprise a complete MiMe genotype, and each of the ancestors comprises a partial MiMe genotype, and when an ancestor is created, the ancestor is further crossed to create the first MiMe parent plant, the second MiMe parent plant, or both; (b) providing clonal gametes from the first MiMe parent plant and the second MiMe parent plant that collectively comprise the three or more haplotypes; (c) crossing the clonal gametes to produce the population of polyploid seeds; The method, wherein the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, and the subpopulation of genetically uniform polyploid seeds comprises the three or more haplotypes.

15. the subpopulation of genetically uniform polyploid seeds has a partially complemented MiMe genotype; (A) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, only non-MiMe alleles at a second MiMe locus of a second MiMe component, and only MiMe alleles at one or more MiMe loci of a third MiMe component; (b) the second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, only MiMe alleles at the second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of the third MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; (i) at least one of the MiMe loci of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only a MiMe allele of the third MiMe component, or (ii) the one or more MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from the one or more MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component; the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis; and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; (B) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; (b) the second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, and only MiMe alleles at the second MiMe locus of the second MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components; (C) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at one or more MiMe loci of a second MiMe component, only MiMe alleles at one or more MiMe loci of a third MiMe component, and only non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination; (b) the second MiMe parent plant has only MiMe alleles at the one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the one or more MiMe loci of the second MiMe component, only non-MiMe alleles at the one or more MiMe loci of the third MiMe component, and only MiMe alleles at the one or more MiMe loci of the fourth MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; 15. The method of claim 14, wherein the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis, (3) components of progression through the second division of meiosis, and (4) components of progression through the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component.

16. 10. A method for producing a population of polyploid seeds according to claim 1, comprising: (a) creating a first MiMe parent plant by introducing genetic modifications into one or more candidate lines to generate MiMe alleles in the germplasm of the first MiMe parent plant or its ancestors, wherein the first MiMe parent plant comprises a complete MiMe genotype and each of the ancestors comprises a partial MiMe genotype, and when ancestors are created, the ancestors are further crossed to create the first MiMe parent plant; (b) providing a clonal gamete from said first MiMe parent plant; (c) providing haploid gametes from a homozygous non-MiMe parent plant; (d) crossing the clonal gametes with the haploid gametes to produce the population of polyploid seeds; The method, wherein the clonal gametes and haploid gametes collectively comprise three or more haplotypes.

17. 1. A method of breeding a polyploid hybrid plant line, comprising: (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate lines of the plant; (c) selecting two or more candidate lines that together contain three or more haplotypes; (d) producing a first MiMe parent plant and a second MiMe parent plant from the two or more candidate lines, the first MiMe parent plant and the second MiMe parent plant collectively comprising the three or more haplotypes; (e) providing clonal gametes from each of the first and second MiMe parent plants; (f) crossing the clonal gametes to produce hybrid polyploid seed containing the three or more haplotypes; (g) cultivating the hybrid polyploid seeds to produce hybrid polyploid plants containing three or more haplotypes; (h) evaluating one or more characteristics of the hybrid polyploid plant; The method optionally comprises: (i) repeating steps (b) through (h) or steps (c) through (h) using the one or more characteristics of the hybrid polyploid plant evaluated in step (h) to guide the breeding of lines in step (b), the selection of candidate lines in step (c), or both.

18. (A) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, only non-MiMe alleles at a second MiMe locus of a second MiMe component, and only MiMe alleles at one or more MiMe loci of a third MiMe component; (b) the second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, only MiMe alleles at the second MiMe locus of the second MiMe component, and only MiMe alleles at one or more MiMe loci of the third MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; (i) at least one of the MiMe loci of the first MiMe parent plant that has only a MiMe allele of the third MiMe component is the same as at least one of the MiMe loci of the second MiMe parent plant that has only a MiMe allele of the third MiMe component, or (ii) the one or more MiMe loci of the first MiMe parent plant that have only a MiMe allele of the third MiMe component are different from the one or more MiMe loci of the second MiMe parent plant that have only a MiMe allele of the third MiMe component; the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis; and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; (B) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at a first MiMe locus of a second MiMe component, and only non-MiMe alleles at a second MiMe locus of the second MiMe component; (b) the second MiMe parent plant has only MiMe alleles at one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the first MiMe locus of the second MiMe component, and only MiMe alleles at the second MiMe locus of the second MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components; (C) (a) the first MiMe parent plant has only MiMe alleles at one or more MiMe loci of a first MiMe component, only MiMe alleles at one or more MiMe loci of a second MiMe component, only MiMe alleles at one or more MiMe loci of a third MiMe component, and only non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, wherein the first MiMe component is a component of a DNA double-strand break during meiotic recombination; (b) the second MiMe parent plant has only MiMe alleles at the one or more MiMe loci of the first MiMe component, only non-MiMe alleles at the one or more MiMe loci of the second MiMe component, only non-MiMe alleles at the one or more MiMe loci of the third MiMe component, and only MiMe alleles at the one or more MiMe loci of the fourth MiMe component; at least one of the MiMe loci of the first MiMe parent plant having only MiMe alleles of the first MiMe component is identical to at least one of the MiMe loci of the second MiMe parent plant having only MiMe alleles of the first MiMe component; 18. The method of claim 17, wherein the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (3) a component of progression through the second division of meiosis, and (4) a component of progression through the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component.

19. 1. A method of breeding a polyploid hybrid plant line, comprising: (a) obtaining a set of plant lines; (b) breeding the lines using conventional plant breeding methods to produce a set of candidate lines of the plant; (c) selecting two or more candidate lines that together contain three or more haplotypes; (d) generating a first MiMe parent plant from one of the two or more candidate lines; (e) providing a clonal gamete from said first MiMe parent plant; (f) providing a haploid gamete from a homozygous non-MiMe parent plant of one of said two or more candidate lines; (g) crossing the clonal gametes with the haploid gametes to produce hybrid polyploid seeds; (h) cultivating the hybrid polyploid seeds to produce hybrid polyploid plants; (i) assessing one or more characteristics of the hybrid polyploid plant; the MiMe parent plant and the homozygous non-MiMe parent plant collectively comprise three or more haplotypes, the crossing in step (g) results in the hybrid polyploid seed comprising three or more haplotypes, and the cultivating in step (h) results in the hybrid polyploid plant comprising three or more haplotypes; The method optionally comprises: (j) repeating steps (b) through (i) or steps (c) through (i) using the one or more characteristics of the hybrid polyploid plant evaluated in step (i) to guide the breeding of lines in step (b), the selection of candidate lines in step (c), or both.

20. 18. The method of claim 17, wherein the first MiMe parent plant, the second MiMe parent plant, the non-MiMe parent plant, or any combination thereof, is diploid, triploid, or tetraploid, and the hybrid polyploid plant is tetraploid, pentaploid, hexaploid, 7ploid, or octaploid.

21. Producing the first MiMe parent plant, the second MiMe parent plant, or both, comprises: (1) directly introducing the complete MiMe genotype into two candidate lines to produce the first MiMe parent plant, the second MiMe parent plant, or both; (2) introducing a partial MiMe genotype into two candidate lines to produce two non-MiMe grandparent plants, each having a partial MiMe genotype, and crossing the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce the first MiMe parent plant, optionally wherein producing the first MiMe parent plant, the second MiMe parent plant, or both, comprises directly introducing a complete MiMe genotype into a third candidate line to produce the second MiMe parent plant; or (3) introducing a partial MiMe genotype into four candidate lines to produce four non-MiMe grandparent plants, each having a partial MiMe genotype, and crossing pairs of the non-MiMe grandparent plants, each having a partial MiMe genotype, to produce the first and second MiMe parent plants; 20. The method of claim 17, wherein optionally, producing the first MiMe parent plant, the second MiMe parent plant, or both, further comprises propagating the first MiMe parent plant, the second MiMe parent plant, the non-MiMe grandparent plant, or any combination thereof, for large-scale production of homogenous seeds.

22. the first MiMe parent plant, the second MiMe parent plant, the hybrid polyploid plant, or any combination thereof, (A) a MiMe allele that confers reduced expression of one or more MiMe loci of each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis; (2) a component of DNA double-strand breaks during meiotic recombination; and (3) a component of progression through the second division of meiosis, and wherein each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; or (B) A MiMe allele that confers reduced expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) a component of DNA double-strand breaks during meiotic recombination; and (4) a component of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component are different MiMe components.

18. The method of claim 17, wherein the patient has a complete MiMe genotype comprising:

23. Each non-MiMe grandparent plant, said hybrid polyploid plant, or a combination thereof, (A) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of the first, second, and third MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first, second, and third MiMe components, the partial MiMe genotype, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; or (B) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of said first and second MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first and second MiMe components, 18. The method of claim 17, wherein the first MiMe component and the second MiMe component are selected from the group consisting of (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and each of the first MiMe component and the second MiMe component has the partial MiMe genotype being a different MiMe component.

24. (1) the one or more MiMe loci of components of meiotic division I sister chromatid cohesion include REC8, SWITCH1 / DYAD, or a combination thereof; (2) the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof; (3) the one or more MiMe loci of components of progression through the second division of meiosis include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof; and / or (4) The method of claim 22, wherein the one or more MiMe loci of components of progression through the first division of meiosis include PS1, JASON, or a combination thereof.

25. The hybrid polyploid plant is (1) A complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic alterations that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (2) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (3) a complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (4) (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) a partial MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1, optionally wherein the population of polyploid seeds is derived from a maize plant and the one or more OSD1 loci comprise OSD1-1 and OSD1-2; (5) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (6) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (7) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (8) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (9) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (10) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (11) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (12) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (13) A complete MiMe genotype comprising: (i) an os allele, wherein the hybrid polyploid plant is homozygous for the os allele; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1. (14) A partial MiMe genotype comprising: (i) an os allele, wherein the hybrid polyploid plant is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (15) A complete MiMe genotype comprising (i) a ps allele, wherein the hybrid polyploid plant is homozygous for the ps allele, and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (16) A partial MiMe genotype comprising: (i) a ps allele, wherein the hybrid polyploid plant is heterozygous for the ps allele; and (ii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1. (17) (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (18) (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (19) (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic alterations that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (20) A partially complemented MiMe genotype comprising: (i) a ps allele, wherein the hybrid polyploid plant is heterozygous for the ps allele; (ii) an os allele, wherein the hybrid polyploid plant is heterozygous for the os allele; (iii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only a MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; or (21) A partially complemented MiMe genotype comprising: (i) an os allele, wherein the hybrid polyploid plant is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1; (iii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1.

18. The method of claim 17, comprising:

26. 18. The method of claim 17, wherein one or more of the candidate lines in step (c) is an inbred line, a hybrid line, or a combination thereof.

27. 22. The method of claim 21, wherein the complete MiMe genotype, the partial MiMe genotype, or both, are introduced by gene editing, gene transfer, or a combination thereof.

28. 23. The method of claim 22, wherein reducing expression of one or more of the MiMe loci is achieved, each independently, by gene disruption, gene knockout, gene knockdown, gene silencing, RNA interference, or induced methylation.

29. 23. The method of claim 22, wherein reducing the expression of one or more of the MiMe loci is achieved by independently introducing into each candidate lineage or an ancestor thereof an insertion, deletion, one or more nucleotide changes, or inversion that results in reduced expression of the MiMe loci, and optionally comprising a step of selecting for reduced expression of the MiMe loci.

30. the insertion, the deletion, the one or more nucleotide changes, or the inversion eliminates expression of the MiMe locus; 30. The method of claim 29, wherein optionally, expression of the MiMe locus is ablated by a premature stop codon present after the first 70%, first 60%, first 50%, first 40%, first 30%, first 20%, or first 10% of nucleotides 3' to the start codon of the coding sequence of the MiMe locus.

31. (a) based on a polyploid plant comprising three or more haplotypes having one or more desired characteristics, providing clonal gametes from a pair of MiMe parent plants comprising together the three or more haplotypes selected using the breeding method of claim 17; (b) crossing the clonal gametes to produce the population of polyploid seeds, The method, wherein the population of polyploid seeds comprises a subpopulation of genetically uniform polyploid seeds in an amount of at least 50% of the total number of seeds, and the subpopulation of genetically uniform polyploid seeds comprises the three or more haplotypes.

32. (a) based on a polyploid plant comprising three or more haplotypes having one or more desired characteristics, selecting the three or more haplotypes using the breeding method of claim 19; (b) providing clonal gametes from a MiMe parent plant; (c) providing haploid gametes from a homozygous non-MiMe parent plant; (d) crossing said clonal gametes with said haploid gametes to produce said population of polyploid seeds, The method, wherein the MiMe parent plant and the homozygous non-MiMe parent plant collectively comprise the three or more haplotypes selected in step (a), and the crossing in step (d) results in a population of polyploid seeds comprising a genetically uniform subpopulation of polyploid seeds in an amount of at least 50% of the total number of seeds, and the genetically uniform subpopulation of seeds comprises the three or more haplotypes.

33. 32. The method of claim 31 , wherein the population of polyploid seeds has a mean pairwise genetic homogeneity of at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% as measured by the Jaccard similarity index.

34. 32. The method of claim 31 , wherein the population of polyploid seeds comprises the genetically uniform subpopulation of polyploid seeds in an amount of at least 70%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% of the total number of seeds.

35. 32. The method of claim 31 , wherein each pair of seeds in the subpopulation of genetically uniform polyploid seeds has a pairwise identity of at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% as measured by the Jaccard similarity coefficient.

36. (A) three or more haplotypes; (B) (i) a complete MiMe genotype comprising MiMe alleles that confer reduced expression of one or more MiMe loci for each of a first, second, and third MiMe component, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis; (2) a component of DNA double-strand breaks during meiotic recombination; and (3) a component of progression through the second division of meiosis, and wherein each of the first MiMe component, the second MiMe component, and the third MiMe component are different MiMe components; ii) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of the first, second, and third MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first, second, and third MiMe components, the partial MiMe genotype, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis, (2) components of DNA double-strand breaks during meiotic recombination, and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component; iii) a complete MiMe genotype comprising MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of a first and a second MiMe component, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) components of DNA double-strand breaks during meiotic recombination, and (4) components of progression during the first division of meiosis, and wherein each of the first MiMe component and the second MiMe component are different MiMe components; iv) (a) one or more MiMe alleles that confer a reduction in expression of one or more MiMe loci of each of said first and second MiMe components; (b) one or more non-MiMe alleles at the one or more MiMe loci of each of the first and second MiMe components, the partial MiMe genotype, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) components of DNA double-strand breaks during meiotic recombination; and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component; v) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component; and (b) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said second MiMe component; (c) a partially complemented MiMe genotype comprising either (i) only MiMe alleles at one or more MiMe loci of a third MiMe component, or (ii) one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of said third MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said third MiMe component, the partially complemented MiMe genotype, wherein the first MiMe component, the second MiMe component, and the third MiMe component are selected from the group consisting of: (1) components of sister chromatid cohesion during the first division of meiosis; (2) components of DNA double-strand breaks during meiotic recombination; and (3) components of progression through the second division of meiosis, and each of the first MiMe component, the second MiMe component, and the third MiMe component is a different MiMe component; vi) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component; and (b) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at a first MiMe locus of a second MiMe component, and one or more MiMe alleles and one or more non-MiMe alleles at a second MiMe locus of said second MiMe component, the partially complemented MiMe genotype, wherein the first MiMe component and the second MiMe component are selected from the group consisting of: (2) components of DNA double-strand breaks during meiotic recombination; and (4) components of progression through the first division of meiosis, and each of the first MiMe component and the second MiMe component is a different MiMe component; or vii) (a) only MiMe alleles at one or more MiMe loci of a first MiMe component, wherein said first MiMe component is a component of a DNA double-strand break during meiotic recombination; (b) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a second MiMe component; and (c) one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a third MiMe component; and (d) a partially complemented MiMe genotype comprising one or more MiMe alleles and one or more non-MiMe alleles at one or more MiMe loci of a fourth MiMe component, A genetically modified plant, plant part, or plant cell comprising the partially complemented MiMe genotype, wherein the second MiMe component, the third MiMe component, and the fourth MiMe component are selected from the group consisting of: (1) a component of sister chromatid cohesion during the first division of meiosis, (3) a component of progression through the second division of meiosis, and (4) a component of progression through the first division of meiosis, and each of the second MiMe component, the third MiMe component, and the fourth MiMe component is a different MiMe component.

37. (1) the one or more MiMe loci of components of meiotic division I sister chromatid cohesion include REC8, SWITCH1 / DYAD, or a combination thereof; (2) the one or more MiMe loci of components of DNA double-strand breaks during meiotic recombination include PAIR1, SPO11-1, SPO11-2, PRD1, PRD2, DFO, MTOPVIB, DSY1, SY1, SY2, SY3, SY4, or any combination thereof; (3) the one or more MiMe loci of components of progression through the second division of meiosis include OSD1, CYCA1, TDM1, PC1, PC2, FC, or any combination thereof; and / or (4) The genetically modified plant, plant part, or plant cell of claim 36, wherein the one or more MiMe loci of components of progression through the first division of meiosis include PS1, JASON, or a combination thereof.

38. (1) A complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic alterations that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (2) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (3) a complete MiMe genotype comprising (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (4) (i) at least one MiMe allele and at least one non-MiMe allele at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) a partial MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1, optionally wherein the population of polyploid seeds is derived from a maize plant and the one or more OSD1 loci comprise OSD1-1 and OSD1-2; (5) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (6) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (7) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (8) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; (9) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (10) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (11) A complete MiMe genotype comprising: (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (12) A partial MiMe genotype comprising: (i) at least one MiMe allele and at least one non-MiMe allele at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic modifications that result in reduced expression of TDM1; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more PAIR1 loci, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; (13) A complete MiMe genotype comprising: (i) an os allele, wherein the genetically modified plant, plant part, or plant cell is homozygous for the os allele; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (14) A partial MiMe genotype comprising: (i) an os allele, wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (15) A complete MiMe genotype comprising (i) a ps allele, wherein the genetically modified plant, plant part, or plant cell is homozygous for the ps allele, and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (16) A partial MiMe genotype comprising: (i) a ps allele, wherein the genetically modified plant, plant part, or plant cell is heterozygous for the ps allele; and (ii) at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (17) (i) only MiMe alleles at one or more OSD1 loci, wherein each of the MiMe alleles at the one or more OSD1 loci comprises one or more genetic modifications that result in reduced expression of OSD1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (18) (i) only MiMe alleles at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic alterations that result in reduced expression of CYCA1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic alterations that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic alterations that result in reduced expression of SPO11-1; (19) (i) only MiMe alleles at one or more TDM1 loci, wherein each of the MiMe alleles at the one or more TDM1 loci comprises one or more genetic alterations that result in reduced expression of TDM1; (ii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic alterations that result in reduced expression of REC8; or (iii) at least one MiMe allele at one or more PAIR1 loci. and at least one non-MiMe allele, wherein each of the MiMe alleles at the one or more PAIR1 loci comprises one or more genetic modifications that result in reduced expression of PAIR1; and (iv) a partially complemented MiMe genotype comprising at least one MiMe allele and at least one non-MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; (20) A partially complemented MiMe genotype comprising: (i) a ps allele, wherein the genetically modified plant, plant part, or plant cell is heterozygous for the ps allele; (ii) an os allele, wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele; (iii) at least one MiMe allele and at least one non-MiMe allele at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only a MiMe allele at one or more SPO11-1 loci, wherein each of the MiMe alleles at the SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1; or (21) A partially complemented MiMe genotype comprising: (i) an os allele, wherein the genetically modified plant, plant part, or plant cell is heterozygous for the os allele; (ii) at least one MiMe allele and at least one non-MiMe allele at one or more CYCA1 loci, wherein each of the MiMe alleles at the one or more CYCA1 loci comprises one or more genetic modifications that result in reduced expression of CYCA1; (iii) only MiMe alleles at one or more REC8 loci, wherein each of the MiMe alleles at the one or more REC8 loci comprises one or more genetic modifications that result in reduced expression of REC8; and (iv) only MiMe alleles at one or more SPO11-1 loci, wherein each of the MiMe alleles at the one or more SPO11-1 loci comprises one or more genetic modifications that result in reduced expression of SPO11-1.

37. The genetically modified plant, plant part, or plant cell of claim 36, comprising:

39. 37. The genetically modified plant, plant part, or plant cell of claim 36, comprising one or more polynucleotide sequences selected from the group consisting of SEQ ID NOs: 448-466, 468-471, 474-491, and 493-496.

40. (i) the genetically modified plant part is a non-regenerable plant part, or 37. The genetically modified plant, plant part, or plant cell of claim 36, wherein (ii) the genetically modified plant cell is a non-regenerable plant cell.

41. 37. The genetically modified plant, plant part, or plant cell of claim 36, wherein the plant part is a flower, pistil, leaf, stem, petiole, cutting, tissue, seed coat, ovule, pollen, tuber, root, rhizome, shoot, fruit, cotyledon, hypocotyl, protoplast, embryo, anther, or part thereof.

42. A processed plant product derived from the genetically modified plant, plant part, or plant cell of claim 36, wherein the processed plant product contains a detectable amount of one or more MiMe alleles of the genetically modified plant, plant part, or plant cell.

43. The plant processed product is (i) selected from the group consisting of plant biomass, oil, meal, food starch, syrup, animal feed, flour, flakes, bran, long fiber, rice husk, and processed seeds; and / or (ii) The plant processed product according to claim 42, which is non-renewable.

44. The germplasm of the polyploid seed population of claim 1.

Images