Improved color-coded male sterile system for targeted selection of cereal plants

Abstract

The present invention relates to a cereal plant comprising an engineered alien addition chromosome carrying a male fertility restorer gene and a co-segregating set of genes contributing to a color characterized by a low misdivision rate. Further the present invention relates to a cell, a seed, or a progeny or part thereof of the cereal plant comprising said male fertility restorer gene and said set of genes. The invention also relates to a method for selecting and / or sorting at least one male-sterile female seed of a cereal plant. The present invention also relates to a method of generating a color-coded male sterile system for phenotypic and / or genetic selection of cereal plants. Further the present invention relates to an engineered alien addition chromosome carrying the above mentioned structural features.

Description

[0001]Munich, 19 September 2025 Our Ref.: KM 5653-02WO CMC / swo Applicant: KWS SAAT SE & Co. KGaA, The University of Sydney Serial Number: New Application KWS SAAT SE & Co. KGaA Grimsehlstraße 31, 37574 Einbeck, GERMANY The University of Sydney Parramatta Road, 2006 SYDNEY, AUSTRALIA Improved color-coded male sterile system for targeted selection of cereal plants Technical Field The present invention relates to a cereal plant comprising an engineered alien addition chromosome carrying a male fertility restorer gene and a co-segregating set of genes contributing to a color phenotype characterized by a low misdivision rate. Further the present invention relates to a cell, a seed, or a progeny or part thereof of the cereal plant comprising said male fertility restorer gene and said set of genes. The invention also relates to a method for selecting and / or sorting at least one male-sterile female seed of a cereal plant. The present invention also relates to a method of generating a color-coded male sterile system for phenotypic and / or genomic selection of cereal plants. Further the present invention relates to an engineered alien addition chromosome carrying the above- mentioned structural features. Background of the invention Wheat (Triticum spp.) is a cornerstone plant of global food security, contributing 20% of the dietary calories and protein consumed by humans and serving as a crucial source of dietary fiber. With over 770 million tons produced annually on more than 217 million hectares, wheat's significance is undeniable, especially as the global population, expected to reach 9.4 billion by 2050, demands 60% more food. However, wheat production faces significant challenges from both biotic (pests, diseases) and abiotic (climate change, drought) stresses, which threaten yield and nutritional value (Alam et al., Emerging Trends in Wheat (Triticum spp.) Breeding: Implications for the Future, Emerging Trends in Wheat, Front. Biosci. (Elite Ed) (2024), 16, 1, 2). *20250422052*  To address these challenges, hybridization of wheat plants plays an essential role. Hybrid wheat offers the potential for higher yields, greater resilience to environmental stresses, and improved resistance to diseases, making it a key strategy in securing the future of wheat production. By harnessing the benefits of heterosis, hybrid wheat plants can better adapt to changing climates and biotic pressures. Thus, hybridization is not only crucial for meeting the rising global demand but also for ensuring the sustainability and stability of wheat production in the face of mounting challenges. The production of hybrid cereal plants, particularly hybrid wheat, necessitates the generation of male-sterile female parents. WO 92 / 01366 A1 describes a male sterility system leveraging a homozygous deletion on the short arm of chromosome 4B in wheat, commonly known as the “Probus” deletion. Male-sterile seeds (mother) are usually produced by selfing a BLA line. This line needs to carry the Probus deletion in a homozygous state. This deletion targets the Ms1 gene, which has been identified as the causative agent for male sterility. The deletion or modification of the Ms1 gene reliably induces male sterility (Probus deletion in a homozygous state), which can be reversed upon crossing with a normal wheat line, thereby restoring fertility in the progeny, which carry the deletion in a heterozygous state. However, maintaining male sterility in female parents necessitates additional components. WO 92 / 01366 A1 teaches the use of a male parent plant, isogenic to the female that possesses an alien addition chromosome. This chromosome bears a dominant male fertility restorer gene from Triticum boeoticum on its short arm and the Blue Aleurone (BLA) locus from Agropyron elongatum (also known as Thinopyrum ponticum) on its long arm. The cross between such a male parent and a male-sterile female parent yields progeny seeds distinguishable by color: blue seeds carrying the BLA locus and normal colored seeds without it. The normal colored seeds, which theoretically remain male-sterile due to the ms1 deletion and lack of the alien addition chromosome, are designated for use in subsequent hybrid wheat production, while the blue seeds may be reserved for maintenance breeding. The currently utilized 42+1 chromosome system, while promising in theory, faces significant practical challenges, particularly concerning the stability of the alien addition chromosome. For commercial application, the normal coloration of seeds must be strictly linked to male sterility to impede unintended self and / or cross-pollination, which would interfere with the whole hybrid generation process. However, the alien addition chromosome undergoes misdivision occurring typically in 1-2% of cases. Such misdivision results in the formation of two telocentric chromosomes: one carrying the blue aleurone locus and the other carrying the fertility restorer gene without the blue seed color locus. This misdivision which is phenotypically observable leads to the unintended generation of blue seeds that are male-sterile and normal colored, including white, seeds that are male- fertile, which significantly disrupts the hybridization process. When, for example, male-sterile blue seeds are used in maintenance crosses, they produce male sterile plants, interrupting the breeding cycle. Conversely, using fertile normal colored (herein usually non-blue) seeds during hybrid production leads to self-fertilization and undesirable cross-pollination. This not only diminishes the yield benefits of hybridization but also introduces a significant yield loss due to the production of contaminant non-hybrid seeds that carry only the female parent's genotype. Furthermore, it can result in less homogenous hybrid seed lots. Moreover, the instability of the alien addition chromosome makes it impossible to rely on differential seed coloring for eliminating unwanted seeds from the population. Currently, cytogenetical determination of the break in the alien addition chromosome is required to detect these issues, a process that is both time-consuming and labor-intensive. Consequently, there is still a need to improve the existing 42+1 chromosome system to make it even more practical for rapid commercial-scale hybrid wheat production, and to meet seed quality standards in many markets. Given the limitations of the current 42+1 chromosome system, there is a high need for plant lines carrying a functional alien addition chromosome that exhibits stable co-segregation of both a set of genes contributing to a specific color phenotype and the male fertility restorer gene. Such a significantly improved chromosome would ensure that seed coloration is a reliable indicator of fertility status, which is the basis of the efficient production of hybrid wheat and thus providing a robust foundation for commercial hybrid wheat systems. Summary of the Invention The above-identified objects are solved by the technical teaching as provided with the present invention. A first aspect relates to a cereal plant comprising an engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes, wherein the set of genes comprises at least one gene cluster and / or at least one individual gene contributing to a color phenotype in the cereal plant, preferably seed coloring, (i) wherein the engineered alien addition chromosome has a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes; and / or (ii) wherein the male fertility restorer gene and the set of genes are independently located within 40%, preferably within 30%, more preferably within 20% relative distance to the centromere or centromeric region of the engineered alien addition chromosome; and / or (iii) wherein the male fertility restorer gene is located on the same chromosomal arm with at least one gene cluster and / or at least one individual gene contributing to the color phenotype; and / or wherein at least one gene cluster and / or at least one individual gene contributing to the color phenotype is located on a different chromosome arm than the male fertility restorer gene. One embodiment relates to the cereal plant according to the first aspect, wherein the at least one gene cluster contributing to the color phenotype is located on the short arm of the engineered alien addition chromosome and the male fertility restorer gene is located on the long arm of the engineered alien addition chromosome. One embodiment relates to the cereal plant according to the first aspect or any embodiment thereof, wherein the at least one individual gene contributing to the color phenotype and the male fertility restorer gene are on the same arm of the engineered alien addition chromosome. One embodiment relates to the cereal plant according to the first aspect or any of the embodiments thereof, wherein the set of genes comprises or consists of F3’5’H480, MYC480, MYB480 and / or MYC616, wherein F35H480, MYC480, MYB480 form a gene cluster, being defined by the sequences as set forth in the embodiment following the sixth aspect, (vii) to (xii). A second aspect relates to a chromosomal unit comprising the set of genes defined in the first aspect or any embodiment thereof and the male fertility restorer gene as defined in the first aspect or any embodiment thereof, wherein said genes are located within a genomic interval, the interval spanning from the gene cluster as defined in the previous embodiment to MYC616 as defined in the previous embodiment and comprising in-between the gene cluster and MYC616 the male fertility restorer gene as in the previous embodiment. One embodiment relates to the cereal plant according to the first aspect or any of the embodiments thereof, wherein the cereal plant comprises, preferably homozygously, a male fertility gene mutation, which is a gene deletion, a gene knockdown, or a gene knockout, preferably wherein the male fertility gene is Ms1 or a nucleic acid as defined comprising a nucleic acid sequence independently selected from the group consisting of: (i) a nucleic acid as set forth in SEQ ID NO: 47, 50, 54 or 57; (ii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 47, 50, 54 or 57; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 48, 51, 55, or 58; (iv) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 48, 51, 55 or 58; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59. As used herein Ms1 refers to functional gene, while ms1 is the non-functional version. One embodiment relates to the cereal plant according to the first aspect or any of the embodiments thereof, wherein the cereal plant comprises one additional chromosome to its euploid number of chromosomes, wherein the male fertility restorer gene and the set of genes as defined in the first aspect or any of the embodiments thereof are on the additional chromosome. One embodiment relates to the cereal plant according to the first aspect or any of the embodiments thereof, wherein the cereal plant is a tetraploid wheat, hexaploid wheat, diploid wheat, or triticale. A third aspect relates to a cell, a seed, or a progeny or part thereof of the cereal plant according to the first aspect or any of the embodiments thereof, or the chromosomal unit according to the second aspect. A fourth aspect relates to a method for selecting and / or sorting of at least one male-sterile female seed of a cereal plant comprising the steps of: (i) separating, preferably automatically separating, from the progeny according to the third aspect a colored seed from an normal seed, wherein the at least one normal seed is male-sterile; and (ii) obtaining a cereal plant, including a hybrid cereal plant, a part of a cereal plant, a progeny thereof, a cell and / or a seed thereof. A fifth aspect relates to a method of generating a color-coded male sterile system for phenotypic and / or genetic selection of a cereal plant comprising: a) selecting a cereal plant line comprising a male fertility gene mutation, preferably wherein the male fertility gene mutation is homozygous, wherein the cereal plant line comprises at least one engineered alien addition chromosome carrying a male fertility restorer gene according to the first and second aspect or any embodiment thereof, and a set of genes as defined according to the first and second aspect or any embodiment thereof, or wherein the cereal line comprises a chromosome comprising a chromosomal unit as defined in the second aspect; and b) optionally: rearranging the at least one engineered alien addition chromosome, wherein the rearranging step comprises using the presence of a gametocidal gene which induces breakage and rearrangement of the at least one engineered alien addition chromosome, to the cereal plant line of step a), wherein the gametocidal gene is located on a monosomic or a disomic gametocidal addition chromosome; and / or c) optionally: applying mutagenesis to at least one cell, seed, plant or part of a plant of the cereal plant line of step a), wherein mutagenesis is selected from genome editing, chemical and radiation induced mutagenesis, or a combination thereof; and (d) obtaining a cereal plant comprising a rearranged engineered alien addition chromosome as defined in the first or second aspect or any embodiment thereof. One embodiment relates to the method according to the fourth or fifth aspect, wherein the engineered alien addition chromosome is monosomic. One embodiment relates to the method according to the fifth aspect or any embodiment thereof, wherein the gametocidal gene is introduced as a monosomic addition chromosome, and / or the gametocidal gene is the gametocidal factor located on chromosome 2CCof Aegilops cylindrica. One embodiment relates to the method according to any of the fourth to fifth aspects and any embodiment thereof, wherein the method additionally comprises (x) screening for and / or for identifying the presence of the engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes as defined in the first aspect or any embodiment thereof, and (y) selecting and / or sorting the at least one seed according to the third aspect based on a color phenotype in the cereal plant contributed by the activity of the set of genes as defined in the first aspect or any embodiment thereof. One embodiment relates to the cereal plant according to the first aspect or any of the embodiments thereof, wherein the engineered alien addition chromosome is additionally modified by mutagenesis and / or genetic engineering, wherein mutagenesis includes chemical mutagenesis, radiation mutagenesis, and genome editing, wherein genome editing includes editing by site-directed nucleases, including zinc-finger nuclease (ZFNs) systems, transcription activator-like effector nuclease (TALENs) systems, meganuclease systems and CRISPR / Cas systems. A sixth aspect relates to an engineered alien addition chromosome, including an isolated engineered alien addition chromosome, as defined in the first aspect or any of the embodiments thereof, or in the third, fourth, or fifth aspects or any embodiment thereof. One embodiment relates to the cereal plant according to the first aspect or any embodiment thereof, or the chromosomal unit according to the second aspect, or the engineered alien addition chromosome according to the sixth aspect, wherein the male fertility restorer gene comprises a nucleic acid sequence selected from the group consisting of: (i) a nucleic acid sequence as set forth in SEQ ID NO: 1; (ii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 1; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 2; (iv) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 2; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 3; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 3; and / or wherein the set of genes comprises a nucleic acid sequence independently selected from the group consisting of: (vii) a nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (viii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (ix) a nucleic acid sequence having a coding sequence of SEQ ID NO: 5, 8, 11 and / or 14; (x) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence of SEQ ID NO: 5, 8, 11 and / or 14; (xi) a nucleic acid sequence encoding an amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15; and (xii) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15. A seventh aspect relates to a set of genetic markers for screening for and / or for identifying a cereal plant comprising an engineered alien addition chromosome according the first, second or sixth aspect, or any embodiment thereof, or for screening, identifying, or mapping the engineered alien addition chromosome according to the sixth aspect or any embodiment thereof, or the chromosomal unit according to the second aspect, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J, and / or at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen or all fourteen marker(s) L, M, N, O, P, Q, R, S, T, U, V, W, X and / or Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively, alone or in combination with at least a set of primers specific for identifying at least one or a combination of gene(s) as defined in SEQ ID NOs: 1, 4, 7, 10 and / or 13. One embodiment relates to the set of genetic markers according to the seventh aspect, wherein, with reference to the genotype deposited as NCIMB 44423, (i) marker A can be detected by a set of primers comprising or consisting of SEQ ID NO: 19 and SEQ ID NO: 20; (ii) marker B can be detected by a set of primers comprising or consisting of SEQ ID NO: 21 and SEQ ID NO: 22; (iii) marker C can be detected by a set of primers comprising or consisting of SEQ ID NO: 23 and SEQ ID NO: 24; (iv) marker D can be detected by a set of primers comprising or consisting of SEQ ID NO: 25 and SEQ ID NO: 26; (v) marker E can be detected by a set of primers comprising or consisting of SEQ ID NO: 27 and SEQ ID NO: 28; (vi) marker F can be detected by a set of primers comprising or consisting of SEQ ID NO: 29 and SEQ ID NO: 30; (vii) marker G can be detected by a set of primers comprising or consisting of SEQ ID NO: 31 and SEQ ID NO: 32; (viii) marker H can be detected by a set of primers comprising or consisting of SEQ ID NO: 33 and SEQ ID NO: 34; (ix) marker J can be detected by a set of primers comprising or consisting of SEQ ID NO: 35 and SEQ ID NO: 36; and (x) marker K can be detected by a set of primers comprising or consisting of SEQ ID NO: 37 and SEQ ID NO: 38, or for an another genotype comprising the chromosomal unit as defined in claim 5, a homologous set of primers having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned primer SEQ ID NOs, respectively. An eighth aspect relates to the use of a set of genetic markers according to the seventh aspect or the embodiment thereof, for screening for and / or for identifying a cereal plant comprising an engineered alien addition chromosome according the first, the second or the third aspect or any embodiment thereof, or for screening, identifying, or mapping the engineered alien addition chromosome according to the sixth aspect or any embodiment thereof, or the chromosomal unit according to the second aspect, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J, and / or at least one of markers L to Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively, alone or in combination with at least a set of primers specific for identifying at least one or a combination of gene(s) as defined in SEQ ID NOs: 1, 4, 7, 10 and / or 13. One embodiment relates to the use of the set of genetic markers according to the seventh aspect for identifying a cereal plant having a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes. The misdivision rate can be determined phenotypically, by assessing plants growing from color-sorted seeds, e.g. by observing fertilized ears. Exemplary methods are demonstrated in Examples 9 and 10. Another aspect of the present invention relates to a method for genomic screening of plant germplasm and / or a plant gene pool through the use of a set of primers as disclosed herein, wherein the method of genomic screening enables the identification and analysis of specific genetic markers within the plant genome. The disclosed primers are designed to amplify targeted regions of the plant genome that are associated with traits of interest, such as specific phenotypic characteristics. By applying these primers in a genomic screening process, the method enables the detection of genetic variants, including single nucleotide polymorphisms (SNPs), insertions, deletions, and other forms of genetic variation, across multiple samples of plant germplasm. The advantage of this method lies in its ability to screen large populations of germplasm efficiently and accurately, which enables breeders and researchers to make informed decisions based on genetic data and may inspire further breeding programs. Certain embodiments relate to cereal plant according to the present invention, wherein a representative sample of seeds of said cereal plant is deposited at NCIMB Ltd. with NCIMB accession number 44423. Preferably, the engineered alien addition chromosome can be obtained or isolated from a seed according to the present invention, wherein a representative sample of seeds of said cereal plant is deposited at NCIMB Ltd. with NCIMB accession number 44423. Brief Description of the Drawings The following detailed description of the embodiments of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, shown in the drawings are embodiments, which are presently exemplified. It should be understood, however, that the invention is not limited to the precise arrangement and instrumentalities of the embodiments shown in the drawings. FIG 1: Schematic representation of male sterile wheat seeds utilized for hybrid seed production, showing 21 chromosome pairs as present in conventional hexaploid wheat and a monosomic engineered alien addition chromosome that complements the chromosome set. F: Chromosome region encoding a fertility gene, B: Chromosome region harboring a set of genes contributing to a color phenotype. FIG 2: A: Misdivision of the alien chromosome during meiosis occurs at a frequency of approximately 1-2%, leading to the production of normal colored (here white) seeds containing the fertility restorer gene. As a result, 1-2% of the white-seeded female plants in an F1 seed production system may exhibit male fertility, allowing them to produce self- fertilized seed. These fertile spikes can furthermore pollinate nearby sterile spikes, ultimately causing up to 10% of the F1 seed to be non-hybrid. B: Schematic illustration showing the chromosomal translocation resulting in the BLA chromosome T4BoS.4BL- 4AgL. T4BoS.4BL-4AgL was generated through Robertsonian translocation between a translocation T4BS.4BL-4AgL and chromosome 4Bo of Triticum boeoticum. F: Gene region encoding a fertility gene, B: Gene region harboring a set of genes contributing to a color phenotype. S and L in the chromosomal arm identifiers refer to the “short” (S) or the “long” (l) chromosome arm. FIG 3A: Exemplary chromosomal structures for the original BLA chromosome with marker positions. Original BLA chromosome (not on scale). A, B, C, D, E, F, G, H, J and K are alien markers mapped to the BLA chromosome according to the sequence of the BLA line. Positions of Rf-Ms1 (Rf), MYC616, MYB618 and the gene cluster (Blue: MYB, MYC and F35H) are depicted. After initial screens using cytology (FISH & GISH), the structure as shown in FIG 3B was determined by sequencing of the complete chromosome. Positions are approximate positions. FIG 3B: BLA variant GC8.2 structure according to sequencing of the complete chromosome. Translocated positions of the male sterility restorer gene TboMs1, MYC616, and a set of genes, e.g. including a three-gene cluster (gene cluster shown in blue, here: MYB, MYC and F35H) and markers (m) F, G, D, and J around the centromeric region as determined are depicted, including approximate chromosomal locations in mega base pairs (Mb or Mbp) after first assembly. FIG 4: Agarose gel showing that BC1F2 plants T36-I8 and T35-L4 have lost a three-gene cluster but retained the Rf-Ms1 (Rf) gene. CS: Chinese Spring. FIG 5: Gel electrophoresis image of a three-gene cluster marker on GC8.2 BC1F2 plants that have Rf and MYC616 genes. Lane D11 is plant T35-L4 (A) and D12 is plant T36-I8 (B). FIG 6: Metaphase cells of GC8.2 plant were hybridized with oligo pools for Ms1 (arrowhead 2) and three-gene cluster (arrowhead 1), and chromosomes were pseudo-colored blue (left panel); sequential FISH on the same cell was performed with centromeric probe 6-J9 (yellow-green fluorescence) and chromosomes were pseudo-colored red (right panel). The signal intensity with centromeric probe is much weaker in tested GC8.2 (#46 and others) than that in the original BLA line AR37, indicated by arrow 3. Ms1 and three-gene cluster oligo pools hybridized to the long and short arm of the rearranged chromosome, respectively. FIG 7: Metaphase cells of an original BLA line AR37 were hybridized with oligo pools for Ms1 (arrowhead 1) and MYC616 (arrowhead 2), and chromosomes were pseudo-colored blue (left panel); sequential FISH on the same cell was performed with centromeric probe 6-J9 (arrowhead 3) and chromosomes were pseudo-colored red (right panel). The signal intensity with centromeric probe is much weaker in tested GC8.2 than that in AR37. FIG 8: Sequential FISH and GISH was performed on the same metaphase cell of GC8.2 plant. (A) FISH using probes Oligo-pSc119.2-1 (green signals) and Oligo-pTa535-1 (red signals) was used to identify individual chromosomes. Chromosomes were counterstained with DAPI and pseudo-colored blue. The arrow indicates a rearranged BLA chromosome (B) Pseudoroegneria stipifolia (St) genomic DNA was used as the probe (yellow-green) for GISH. Chromosomes were counterstained with DAPI and pseudo-colored red. (C) For ABD-GISH, total genomic DNA from Triticum urartu and Aegilops tauschii was labeled with fluorescein-12-dUTP and tetramethyl-rhodamine- 5-dUTP, which fluoresced green and red, respectively. Total genomic DNA of Ae. speltoides was used as a blocker and appeared as blue in color due to the DAPI counterstain. Arrowhead points to the centromere of rearranged BLA chromosome T4BoS.4BL-4AgL. (D) The panel on the left shows the rearranged BLA chromosome cut out from A, B, and C. FIG 9: The red channel extracted from FIG 8, displayed as a grayscale image. FIG 10: The green channel extracted from FIG 8, displayed as a grayscale image. FIG 11: Determination of positions of loci Ms1 and MYC_616 in a GC8.2 plant. Two metaphase cells (upper and lower panels) were exposed / stained with oligo pools as probes for loci Ms1 (A, B) and MYC_616 (A, C), respectively. Oligo pools for loci Ms1 and MYC_616 were labelled with Alexa 488 (green fluorescence) and ATTO 550 (red fluorescence), respectively. (A) Composite images with both probes. Chromosomes were counterstained with DAPI and fluoresced blue. Both probes were shown to be at the same or very close location, which are at the proximal region of the long arm. (B) Images taken under the FITC filter. Arrowheads point to the Ms1 signals. (C) Images taken under the TRITC filter. Arrowheads point to the MYC_616 signals. FIG 12: Marker 4BS-HX detects Probus deletion. Blue fertile, normal colored male-sterile, and normal colored male-fertile lines are from the development of BLA system. CS: Chinese Spring (A). The marker Rf-CD was utilized to detect the presence of the Ms1 gene in a segregating population. The Ms1 gene was identified in samples 1, 3, 6, 8, and 9, while it was absent in the remaining samples. Sample 10 served as the positive control for BLA, and Chinese Spring (CS) functioned as the negative control in this assay (B) Marker F35H- CD detected blue gene locus in a segregating population (1 to 9), BLA and C.S. (Chinese Spring) were used as positive and negative controls, respectively. Samples 3, 5, and BLA contained blue three-gene cluster (C). Agarose gel showing KASP marker 2U detected 2Ccchromosome. CS: Chinese Spring; AR5: a BLA line; Gc: Ae. caudata (CC) (D). FIG 13: Confirmation that P4-8-1 has lost the MYC616 by using a so-called MYC616 co- dominant (“CD”) marker MYC616-CD on an agarose gel. FIG 14: Specific markers for the three-gene cluster amplified a band for each gene in GC8.2 (1), but not in Chinese Spring (2). The successful performance of these markers in GC8.2 suggests the presence of the corresponding genes in this species. Primers used for F35H are F35H480-sp-F and F35H480-sp-R; for the MYC480-2 PCR product the used primers were MYC480-sp-F2 and MYC480-sp-R; for MYB the used primers were MYB480-sp-F and MYB480-sp-R. For the MYC480-1 PCR product, the used primers were MYC480-sp- R and MYC480-sp-F1. FIG 15: Cytological analysis of chromosomes in the original BLA system. Sequential FISH (A) and GISH (B, C) were performed on the same metaphase cell. (A) Chromosomes were hybridized with probes Oligo-pSc119.2-1 labeled with 6-carboxyfluorescein (6-FAM) and Oligo-pTa535-1 labeled with 6-carboxytetramethylrhodamine (Tamra) to generate green and red signals, respectively, enabling identification of individual chromosomes. Chromosomes were counterstained with 4’,6-diamidino-2-phenylindole (DAPI) and pseudo-colored blue. (B) Pseudoroegneria stipifolia (St) genomic DNA was used as the probe (yellow-green) for GISH. Chromosomes were counterstained with DAPI and pseudo- colored red. (C) For ABD-GISH, total genomic DNA from Triticum urartu and Aegilops tauschii was labeled with fluorescein-12-dUTP and tetramethyl-rhodamine- 5-dUTP, which fluoresced green and red, respectively. Total genomic DNA of Ae. speltoides was used as a blocker and appeared as brown in color. Arrows point to the breakpoint in the BLA chromosome T4BoS.4BL-4AgL. FIG 16: Hybridisation patterns on metaphase cells of an original BLA line AR37 using oligo pools of four loci, Ms1 (arrowhead 1) and MYC_616 (arrowhead 2) (A, B; labeled with ATTO 550 and fluoresced red), and three-gene cluster (arrowhead 3) and MYB_618 (arrowhead 4) (C, D; labeled with Alexa 488, fluoresced green but pseudo-colored red). Ms1 hybridised to the distal end of short arm of the BLA chromosome (A, B); three-gene cluster hybridized to the middle of the long arm of the BLA chromosome (C, D); both MYC_616 (A, B) and MYB_618 (C, D) hybridised to the distal end of the long arm of the BLA chromosome, and the distal 45% of the long arm of wheat chromosome 4B / 4D, respectively. FIG 17: Models on the generation of BLA chromosome. BLA chromosome was generated through Robertsonian translocation between a whole-arm translocation T4BS.4AgL and chromosome 4Bo of Triticum boeoticum (Li et al., Selection and identification of wheat alien translocation chromosome 4BS.4AgL. J Xi’an United University (2001) 4:16-21) (A). The correct model is that the BLA chromosome T4BoS.4BL-4AgL was generated through Robertsonian translocation between a translocation T4BS.4BL-4AgL and chromosome 4Bo of Triticum boeoticum (B). FIG 18: Schematic structure of the original BLA chromosome (preliminary assembly). The short arm is from Triticum boeoticum (A genome; ~260Mb); the proximal long arm is from wheat chromosome 4BL (~260 - ~440Mb) and the distal long arm is from Thinopyrum ponticum (~440 - ~621Mb). The positions of the genes, Ms1, three-gene cluster (MYB / MYC / F35H), MYC, and MYB, are shown. Brief Description of Sequences SEQ ID NO: Description 1 genomic DNA of male fertility restorer gene Rf-Ms1 2 CDS of male fertility restorer gene Rf-Ms1 3 Rf-Ms1 protein 4 genomic DNA of MYB480 5 CDS of MYB480 6 MYB480 protein 7 genomic DNA of MYC480 8 CDS of MYC480 9 MYC480 protein 10 genomic DNA of F35H480 11 CDS of F35H480 12 F35H480 protein 13 genomic DNA of MYC616 14 CDS of MYC616 15 MYC616 protein 16 genomic DNA of MYB618 17 CDS of MYB618 18 MYB618 protein 19 - 38 Marker primer sequences for the GC8.2 engineered artificial chromosome according to Table 3 39 Marker forward sequence for MYC616 40 Marker reverse sequence for MYC616 41 Marker forward sequence for F35H480 42 Marker reverse sequence for F35H480 43 Marker forward sequence for MYC480 44 Marker reverse sequence for MYC480 45 Marker forward sequence for MYB480 46 Marker forward sequence for MYB480 47 genomic DNA of Hordeum vulgare Ms1 gene 48 CDS of Hordeum vulgare Ms1 gene 49 Hordeum vulgare Ms1 protein 50 genomic DNA of Triticum aestivum Ms1 gene 51 CDS of Triticum aestivum Ms1 gene 52 Triticum aestivum Ms1 protein 53 DNA of synthetic Ms1 54 genomic DNA of Oryza sativa Ms1 gene 55 CDS of Oryza sativa Ms1 gene 56 Oryza sativa Ms1 protein 57 genomic DNA of Brachypodium distachyon Ms1 gene 58 CDS of Brachypodium distachyon Ms1 gene Brachypodium distachyon Ms1 protein 4BS-HX-F primer 4BS-HX-R primer Ms1BoEx3-F primer Ms1m-R primer Rf-CD-F335 primer Rf-CD-R740 primer ThMYC4ESpF primer ThMYC4ESpR primer F35H-CD-F919 primer F35H-CD-R1088 primer 2U-Gc KASP primer 2U-2AS KASP primer 2U-common KASP primer MYC616-CD-F primer MYC616-CD-R primer Blue gene marker sequence Triticum boeoticum Ms1 marker sequence IWB34257-X KASP primer IWB34257-Y KASP primer IWB34257-com KASP primer IWA7268-X KASP primer IWA7268-Y KASP primer IWA7268-com KASP primer F35H-BLA-X KASP primer F35H-4D-Y KASP primer F35H-com KASP primer F35H480-sp-F primer F35H480-sp-R primer MYC480-sp-F2 primer MYC480-sp-R primer MYB480-sp-F primer MYB480-sp-R primer we07652s01as003 X KASP primer we07652s01as003 Y KASP primer we07652s01as003 com KASP primer we07652s01as003 marker sequence we42657s01as002 X KASP primer we42657s01as002 Y KASP primer we42657s01as002 com KASP primer we42657s01as002 marker sequence we43273s01as002 X KASP primer 101 we43273s01as002 Y KASP primer 102 we43273s01as002 com KASP primer 103 we43273s01as002 marker sequence 104 we74781s01as002 X KASP primer 105 we74781s01as002 Y KASP primer 106 we74781s01as002 com KASP primer 107 we74781s01as002 marker sequence 108 Nucleic acid sequence of marker F 109 Nucleic acid sequence of marker G 110 Nucleic acid sequence of marker D 111 Nucleic acid sequence of marker J 112 Nucleic acid sequence of marker L 113 Nucleic acid sequence of marker Y 114 Nucleic acid sequence of marker M 115 Nucleic acid sequence of marker N 116 Nucleic acid sequence of marker O 117 Nucleic acid sequence of marker P 118 Nucleic acid sequence of marker Q 119 Nucleic acid sequence of marker R 120 Nucleic acid sequence of marker S 121 Nucleic acid sequence of marker T 122 Nucleic acid sequence of marker U 123 Nucleic acid sequence of marker V 124 Nucleic acid sequence of marker W 125 Nucleic acid sequence of marker X Definitions The term “cereal plant” or “cereal plant line” refers to cereal plant lines, whole plants, plant organs, plant tissues, seeds, plant cells, seeds and progeny of the same. Cereal plant cells include, but are not limited to, cells from seeds, embryos, zygotes, sporophytes, pollen, microspores, suspension cultures, meristematic regions, callus tissue, leaves, roots, shoots, gametophytes, protoplasts, and plastids. A “part of a plant” includes differentiated and non-differentiated tissues including, without limitation to, roots, stems, shoots, leaves, pollen, seeds, flowers, consumables (e.g., cereal grains), tumor tissue, plant cells, and plant cell cultures. Cereal plant tissue encompasses plant cells and may be in a plant or in a plant organ, tissue or cell culture. Cereal plant tissue also refers to any clone of such a plant, seed, progeny, propagule whether generated sexually or asexually, and descendants of any of these, such as cuttings or seed. Cereal plant organ refers to plant tissue or a group of tissues that constitute a morphologically and functionally distinct part of a plant. A “co-segregating set of genes” is used to express that a group of genes that are inherited together during the process of meiosis because they are located close to each other on the same chromosome. Due to their physical proximity, these genes tend to be passed on as a unit from parent to offspring, exhibiting similar inheritance patterns. This phenomenon occurs because the likelihood of recombination (crossing over) between these genes is low, causing them to "co-segregate" or be inherited together in a population. The terms “crossed” or “cross” or “crossing” are defined as the fusion of gametes via pollination to produce progeny (i.e., cells, seeds, or plants). The term encompasses both sexual crosses (the pollination of one plant by another) and self-fertilization (selfing, self- pollination, i.e., when the pollen and ovule (or microspores and megaspores) are from the same plant or genetically identical plants). “Blue aleurone (BLA)” refers to a genetic trait in certain wheat varieties where the aleurone layer, a tissue found in the seeds, exhibits a blue pigmentation. This coloration is due to the presence of specific pigments, such as anthocyanins, which are influenced by the expression of certain genes, which may be termed “blue aleurone genes”. The “centromere” is a specialized chromosomal region essential for the proper segregation of chromosomes during cell division. It is characterized by a unique chromatin structure, distinguished by the presence of the centromere-specific histone H3 variant known as CENH3 (or CenH3), which replaces the canonical histone H3 within the nucleosomes of the centromeric region. This modification is a key determinant of centromere identity, as it facilitates the assembly of the kinetochore, a protein complex that mediates the attachment of chromosomes to spindle microtubules during mitosis and meiosis. The centromere is typically composed of highly repetitive DNA sequences, such as satellite repeats, though the specific sequence composition can vary significantly among different plant species. These repetitive sequences, while not coding for proteins, are crucial for the structural and functional integrity of the centromere. The establishment and maintenance of centromeric identity are governed largely by epigenetic mechanisms, with the deposition of CENH3 being a central factor. This epigenetic regulation ensures that the centromere remains functionally defined not solely by its DNA sequence but by the specific chromatin state and associated proteins, enabling it to recruit and organize the kinetochore. The term “chromosomal unit” as used herein refers to a specific structural and functional configuration as part of a chromosome that are inherited together as a single genetic arrangement with a very high degree of stability. The chromosomal unit may be delineated as an interval on the chromosome defined by flanking genes, non-coding sequences, genetic markers and / or mapped physical coordinates. In particular, the interval may be bounded by two or more genetic markers (e.g., SNPs, microsatellites / SSRs, insertion– deletion polymorphisms, or sequence-tagged sites) that co-segregate with the male fertility restorer gene and the set of genes as determined by linkage analysis; such interval may be expressed by its genetic map distance (centimorgans) and corresponding recombination fraction. Alternatively, or additionally, the interval may be specified by physical base-pair coordinates on a stated reference genome assembly for the species or engineered chromosome (e.g., chrN:position1–position2), including equivalent coordinates in successor assemblies established via liftover or whole-genome alignment. Cytogenetic descriptors (e.g., chromosome arm identity, banding region, and / or proximity to the centromere) may also be used to define or determine the interval, or by any method known in the art. A “CRISPR nuclease”, as used herein, is a specific form of a site-directed nuclease and refers to any nucleic acid guided nuclease which has been identified in a naturally occurring CRISPR system, which has subsequently been isolated from its natural context, and which preferably has been modified or combined into a recombinant construct of interest to be suitable as tool for targeted genome engineering. Any CRISPR nuclease can be used and optionally reprogrammed or additionally mutated to be suitable for the various embodiments according to the present invention as long as the original wild-type CRISPR nuclease provides for DNA recognition, i.e., binding properties. CRISPR nucleases also comprise mutants or catalytically active fragments or fusions of a naturally occurring CRISPR effector sequences, or the respective sequences encoding the same. A CRISPR nuclease may in particular also refer to a CRISPR nickase or even a nuclease-dead variant of a CRISPR polypeptide having endonucleolytic function in its natural environment. A variety of different CRISPR nucleases / systems and variants thereof are meanwhile known to the skilled person and include, inter alia, CRISPR / Cas systems, including CRISPR / Cas9 systems (EP2771468), CRISPR / Cpf1 systems (EP3009511B1), CRISPR / C2C2 systems, CRISPR / CasX systems, CRISPR / CasY systems, CRISPR / Cmr systems, CRISPR / MAD systems, including, for example, CRISPR / MAD7 systems (WO2018236548A1) and CRISPR / MAD2 systems, CRISPR / Cas^ systems (Pausch et al., Science, 2020, 10.1126 / science.abb1400), CRISPR / CasZ systems and / or any combination, variant, or catalytically active fragment thereof. A nuclease may be a DNAse and / or an RNAse, in particular taking into consideration that certain CRISPR effector nucleases have RNA cleavage activity alone, or in addition to the DNA cleavage activity. “Euploidy” is defined as the condition in which a cell or an organism has one or more complete sets of chromosomes. In other words, the number of chromosomes is an exact multiple of the haploid number (n), which is the number of chromosomes in a single complete set. A “fertile plant” is a plant that produces viable male and female gametes and is self-fertile. Such a self-fertile plant can produce a progeny plant without the contribution from any other plant of a gamete and the genetic material contained therein. Other embodiments of the disclosure can involve the use of a plant that is not self-fertile because the plant does not produce male gametes, or female gametes, or both, that are viable or otherwise capable of fertilization. A “gene cassette” is a distinct DNA sequence that contains one or more genes and is usually flanked by recognition sites that allow it to be inserted, removed, or rearranged within a genome or plasmid through site-specific recombination. A “gene cluster” refers to a group of two or more genes that are physically located in close proximity to one another on the same chromosome. A defining characteristic of a gene cluster is that the constituent genes are often functionally related, for example, by encoding enzymes for the same metabolic pathway or proteins that form a complex. Due to their close physical proximity, the likelihood of meiotic recombination (crossing over) occurring between the genes within a cluster is very low. Consequently, a gene cluster is usually inherited as a single unit and represents a specific instance of "genetically linked" genes. While "genetically linked" broadly describes any set of genes that co-segregate more often than by random chance due to their position on the same chromosome, the term "gene cluster" more specifically implies both this tight genetic linkage and a shared or coordinated biological function among the genes. “Gene knockdown” refers to a genetic technique used to reduce or suppress the expression of a specific gene, leading to a decrease in the production of the gene's corresponding protein. “Gene knockout” involves the complete inactivation or deletion of a specific gene in an organism's genome, resulting in the total loss of function of that gene. “Genetic selection”, also known as phenotypic selection, is a traditional form of selection, wherein plants are selected based on phenotypes, including visually inspectable phenotypes (in contrast to genomic selection on genome level, using markers, primers, probes and the like). This method relies on the direct assessment of traits such as height, yield, resistance to diseases, and other morphological characteristics. This approach does not necessarily require knowledge of the genetic makeup of the plants. The term “genetically linked” relates to a set of genes residing on the same physical chromosome and are arranged such that meiotic recombination between them is sufficiently infrequent that they function operationally as a single inheritable locus, i.e. a chromosomal unit as used herein. The constituent loci may be positioned on the same or opposite chromosome arms (e.g., including pericentromeric locations), and linkage may be achieved either by native organization or by deliberate engineering (e.g., targeted insertion, translocation, or chromosomal fusion) that places the loci onto a single chromosome; once so integrated, they are genetically linked within the resulting chromosomal unit. “Homozygosity” refers to the genetic condition in which an individual has two identical alleles for a particular gene or genetic locus. A “hybrid plant” or “hybrid cereal plant” is defined as a first generation offspring derived from a cross between two genetically different parents. In certain embodiments, hybrid plant or hybrid cereal plant includes all first generation progeny, defined as the F1 or filial generation, developed from a cross between two individual plants with different genotypes. “Irradiation” refers to radiation treatment for chromosome breakage and rearrangement can include, but are not limited to X-rays, fast neutrons, gamma rays, ultraviolet, mixed high- energy particles, and ion beams. The choice of radiation treatment can be related to the type of materials to be treated and the expected / desired frequency and spectrum of mutations. Fast neutrons can induce relatively small segmental deletions or chromosomal translocations in the genome. In contrast, X-rays and gamma rays offer deeper tissue penetration, high reproducibility in mutagenesis experiments, and a higher frequency of chromosomal translocations, with reduced issues related to radioactive waste disposal. X- rays typically emit energy in the range of 50–300 keV and can penetrate plant tissue from a few millimeters to several centimeters, depending on the tissue type and density. Gamma rays, commonly used for mutagenesis, are generated by the decay of radioisotopes, emitting energy up to several MeV. Due to their high energy, gamma rays can penetrate plant tissues completely, reaching all internal structures. This makes gamma rays particularly useful in inducing mutations across entire plant organisms. Neutron energy may be classified into categories such as fast, slow, and thermal, depending on the neutron's kinetic energy. Neutrons are typically produced in nuclear reactors or particle accelerators. Thermal neutrons have energies below 1 eV, while fast neutrons possess energies in the range of several MeV. Neutron energies span from less than 1 eV to several MeV. Due to their high penetration ability, neutrons can travel several centimeters into biological tissues, including plant tissue. A “male sterile plant” is a plant that does not produce, or disperse, male gametes that are viable or otherwise capable of fertilization. As used herein, a “female sterile plant” is a plant that does not produce female gametes that are viable or otherwise capable of fertilization. It is recognized that male-sterile and female-sterile plants can be female-fertile and male- fertile, respectively. It is further recognized that a male fertile (but female sterile) plant can produce viable progeny when crossed with a female fertile plant and that a female-fertile (but male-sterile) plant can produce viable progeny when crossed with a male fertile plant. "Misdivision rate" usually refers to the frequency at which errors occur during the segregation of a chromosome set or a specific chromosome during meiosis, resulting in improper distribution of that chromosome’s genetic material to daughter cells, thereby causing forms of aneuploidy, or other chromosomal changes or rearrangements. Using phenotypic assessment, it can be determined, for example, by counting the occurrence of white seeds that turn into fertile plants producing white seeds within the ambit of the present invention. "Misdivision rate" as used herein may also refer to a “centromere misdivision rate”. At the chromosomal level, misdivision describes the disruption of a chromosome and its unequal distribution to daughter cells, which also affects the segregation of genes located on that chromosome. Normally, closely linked genes would co-segregate; however, during a misdivision event, these genes may be separated. Generally, misdivision is defined as a chromosomal splitting event that leads to the separation of unique marker loci / genes that would typically co-segregate. Specifically, this may refer to the separation a male sterility gene and a set of genes controlling color phenotype in a plant. The misdivision rate in such cases can be influenced by the structural architecture of the chromosome, including the physical location of the marker loci / genes within specific regions of the chromosome and / or the overall architecture of the chromosome. Preferably, a restorer and a set of genes contributing to a color phenotype as disclosed herein may thus be mutually positioned on an alien addition chromosome in a way resulting in a very low misdivision rate with respect to the respective color phenotype. One advantageous embodiment may involve marker genes and loci located on the same chromosome arm, where their close physical proximity increases the likelihood of co- segregation. This occurs because such genes benefit from the structural integrity of the chromosome arm, which remains unaffected by improper centromere splitting, thus minimizing their separation during meiosis. In contrast, genes positioned on different chromosome arms may experience a reduced misdivision rate if the chromosome's structural features, such as a smaller centromere, confer greater stability to the chromosome. This arrangement reduces the risk of improper centromere splitting, ensuring that the chromosome arms, and the linked genes or gene sets, remain intact and co- segregate correctly during meiotic division. Thus, by optimizing the structural design of the chromosome, such as centromere size and / or the positioning of genes on the same arm, the misdivision rate can be minimized, which promotes the stable inheritance of linked genes. In plants, the misdivision rate of a specific chromosome is assessed by examining the offspring or cells that result from meiosis to determine the presence of aneuploidy. Cytogenetic techniques, such as chromosome staining and microscopy, are commonly used to observe and quantify the incorrect segregation of the chromosome. Additionally, molecular methods like fluorescent in situ hybridization (FISH) can be employed to detect and measure the misdivision of the chromosome by identifying its specific markers, allowing researchers to estimate how often misdivision occurs for that chromosome in a given population or under specific conditions. A “monosomic addition chromosome” refers to a genetic condition in which an organism, typically a plant, has an extra chromosome added to its complete set of chromosomes, resulting in a total chromosome count that includes the organism's full complement of chromosomes plus one additional chromosome from another species or source. Monosomic addition lines are particularly valuable for identifying the functions of individual chromosomes and for transferring desirable traits across species. “Mutagenesis” refers to a technique, by which modifications or mutations are introduced into a nucleic acid sequence in a random or non- site-specific way. For example, mutations can be induced by certain chemicals such as EMS (ethylmethanesulfonate) or ENU (N- ethyl-N-nitrosourea) or physically, e.g., by irradiation with UV or gamma rays. Chemical- or radiation-induced mutagenesis is well established in the art and may be performed by any known suitable method, such as but not limited to EMS mutagenesis or UV mutagenesis. As chemical- or radiation-induced mutagenesis is a random mutagenesis approach, the effect of mutagenesis in the form of at least one modification, including at least one point mutation, comprising at least one deletion, insertion and / or substitution. A “nucleic acid construct”, “construct” or “expression construct” refers to a nucleic acid molecule encoding or comprising one or more genetic elements, which upon introduction into a target cell can be transcribed and / or translated into a functional form, e.g. RNA(s) or polypeptide(s) or protein(s). A nucleic acid construct may also comprise regulatory sequences such as promoter and terminator sequences facilitating expression of the genetic element(s) as well as spacers and introns. The genetic elements of the present invention can also be encoded on a set of constructs, which constructs can be introduced into a cell simultaneously or consecutively. The terms "plant" or "plant cell" or “part of a plant” as used herein refer to a plant organism, a plant organ, differentiated and undifferentiated plant tissues, plant cells, seeds, and derivatives and progeny thereof. Plant cells include without limitation, for example, cells from seeds, from mature and immature cells or organs, including embryos, meristematic tissues, seedlings, callus tissues in different differentiation states, leaves, flowers, roots, shoots, male or female gametophytes, sporophytes, pollen, pollen tubes and microspores and protoplasts. A “set of genes” refers to one or more genes that, acting either individually or collectively, that contribute to a color phenotype in the cereal plant, preferably seed coloring. The structural composition of this set is flexible and may comprise a single gene, a single gene cluster, a set of multiple gene clusters, or any combination of individual genes and / or gene clusters. Within the context of the present invention, the components of this set of genes are preferably genetically interlinked such that they are inherited together. The term “contributes” or “contributing to” is to be interpreted in its broadest sense and is not limited to the direct causation of the phenotype. For example, a gene or set of genes is understood to "contribute" to the seed color phenotype if it: (i) encodes an enzyme, transcription factor, or structural protein that is part of the biochemical pathway leading to pigment production; (ii) regulates, either by activation or suppression, the expression of another gene involved in the color phenotype; or (iii) is otherwise functionally involved, even if indirectly, in the metabolic or regulatory cascade that results in the final visible color trait. A “site-directed nuclease” herein refers to a nuclease or an active fragment thereof, which is capable of specifically recognizing and cleaving DNA at a certain location, the target sequence. Such nucleases typically produce a double-strand break (DSB), which is then repaired by non-homologous end-joining (NHEJ) or homologous recombination (HR). Site- directed nucleases include meganucleases, homing endonucleases, zinc finger nucleases, transcription activator-like nucleases and CRISPR nucleases, or variants including nickases or nuclease-dead variants thereof. “TILLING” (Targeting Induced Local Lesions in Genomes) is a process, which allows to identify mutations in a specific gene after an (unspecific) mutagenesis has been performed. Mutagenesis may e.g., be performed using a chemical mutagen such as EMS. Then, a sensitive DNA screening technique is used to identify single base mutations. Methods for performing TILLING are known to the skilled person. “Transformation” or “Transfection” of a plant cell with a construct or set of constructs refers to any established technique to introduce nucleic acid molecules into a cell, such as biolistic approaches (e.g. particle bombardment), microinjection, permeabilising the cell membrane with various treatments such as electroporation or PEG treatment or Agrobacterium tumefaciens mediated transformation, or any combination thereof. Generally, incorporating (a) nucleic acid construct(s), for example by way of transformation, may be accomplished with techniques that are basically known to the person skilled in the art. For example, the nucleic acid construct can be incorporated into the plant cells by infecting a plant tissue or a plant cell with Agrobacterium tumefaciens containing the nucleic acid sequence to be transferred in its plasmid that can be integrated into the plant genome. Incorporating by means of a biolistic transfer is another option, wherein the nucleic acid construct to be incorporated into the plant cell is applied to gold particles or tungsten particles, which are then shot into the cells at a high speed. Another option known to the person skilled in the art for incorporating a nucleic acid construct into a plant cell, is the protoplast transformation, wherein either polyethylene glycol is added to the protoplasts in the presence of the nucleic acid molecules to be incorporated, or the protoplasts are exposed to a short current impulse, so that the protoplast membrane transiently becomes permeable for the nucleic acid construct(s). A “transgenic plant” is defined as a plant which comprises within its genome a heterologous polynucleotide introduced by a transformation step. The heterologous polynucleotide may be stably integrated within the genome such that the polynucleotide is passed on to successive generations. The heterologous polynucleotide may be integrated into the genome alone or as part of a recombinant DNA construct. A transgenic plant can also comprise more than one heterologous polynucleotide within its genome. Each heterologous polynucleotide may confer a different trait to the transgenic plant. A heterologous polynucleotide can include a sequence that originates from a foreign species, or, if from the same species, can be substantially modified from its native form. Transgenic can include any cell, cell line, callus, tissue, plant part or plant, the genotype of which has been altered by the presence of heterologous nucleic acid including those transgenics initially so altered as well as those created by sexual crosses or asexual propagation from the initial transgenic. The alterations of the genome (chromosomal or extra-chromosomal) by conventional plant breeding methods, by the genome editing procedure described herein that does not result in an insertion of a foreign polynucleotide, or by naturally occurring events such as random cross-fertilization, non-recombinant viral infection, non- recombinant bacterial transformation, non-recombinant transposition, or spontaneous mutation are not intended to be regarded as transgenic. The term “vector” refers to an element used for introducing a nucleic acid construct or set of nucleic acid constructs into a cellular system. The vector may be a plasmid or plasmid vector, cosmid, artificial yeast artificial chromosomes (YAC), bacterial artificial chromosome (BAC) or P1 artificial chromosomes (PACs), phagemid, bacterial phage based vector, an isolated single-stranded or double-stranded nucleic acid sequence, comprising DNA and RNA sequences in linear or circular form, or a mixture thereof, for introduction or transformation into a plant, plant cell, tissue, organ or material according to the present disclosure. Whenever the present disclosure relates to the percentage of identity of nucleic acid or amino acid sequences to each other these values define those values as obtained by using the EMBOSS Water Pairwise Sequence Alignments (nucleotide) programme (www.ebi.ac.uk / Tools / psa / emboss_water / ) nucleic acids or the EM-BOSS Water Pairwise Sequence Alignments (protein) programme (www.ebi.ac.uk / Tools / psa / emboss_water / ) for amino acid sequences. Alignments or sequence comparisons as used herein refer to an alignment over the whole length of two sequences compared to each other. Those tools provided by the European Molecular Biology Laboratory (EMBL) European Bioinformatics Institute (EBI) for local sequence alignments use a modified Smith-Waterman algorithm (see www.ebi.ac.uk / Tools / psa / and SMITH, T.F.5 & WATERMAN, M.S. "Identification of common molecular subsequences" Journal of Molecular Biology, 1981147 (1):195-197). When conducting an alignment, the default parameters defined by the EMBL-EBI are used. Those parameters are (i) for amino acid sequences: Matrix = BLOSUM62, gap open penalty = 10 and gap extend penalty = 0.5 or (ii) for nucleic acid sequences: Matrix = DNAfull, gap open penalty = 10 and gap extend penalty = 0.5. The skilled person is well aware of the fact that, for example, a sequence encoding a protein can be ''codon-optimized'' if the respective sequence is to be used in another organism in comparison to the original organism a molecule originates from. Detailed Description The present invention solves the problem of significantly improving the production, maintenance and stability of hybrid cereal plant lines by addressing the critical challenges associated with the current 42+1 chromosome system. Specifically, to reduce the rate of misdivision of the alien addition chromosome, which can lead to the production of unmarked or normal colored fertile seeds (e.g., including white- colored) or marked or colored sterile seeds (e.g., blue-colored), the invention introduces a highly restructured alien addition chromosome. Notably, the term “normal colored” or “unmarked” seed as used herein, particularly in the context of wheat as cereal, usually refers to a white, red, light red, or any shade of red grain phenotype that is usually used as marketing class. All these colors (white, red, light red) can be used in conjunction with a BLA system as used herein, and all will produce blue seed. Regarding the different “normal colors”, the distribution thereof historically depends on the predominance of different germplasm in different regions across the world. In certain embodiments, the centromeric region according to the engineered architecture may the same as in the original chromosome, or it may be shortened. A shortening could additionally reduce the likelihood of improper separation, thereby minimizing the incidence of misdivisions that could result in the formation of unmarked fertile seeds or marked male sterile seeds. The centromeres in higher organisms have a complex, compound structure, rather than being a simple, uniform unit. This complexity means that the centromere consists of multiple functional regions that collectively play a crucial role in cell division. This variability in breakage points underscores the idea that the centromere's structure influences its stability, and that due to redundancy in these regions, such as in wheat, centromeres can be significantly reduced in size or rearranged without affecting function (Zhang et al., The centromere structure in Robertsonian wheat-rye translocation chromosomes indicates that centric breakage-fusion can occur at different positions within the primary constriction, Chromosoma (2001), 110, 5, 335-344). Notably, wheat centromeres contain a substantial amount of highly repetitive DNA sequences, and it has been demonstrated that there is considerable redundancy in these regions (Walkowiak et al., Multiple wheat genomes reveal global variation in modern breeding, Nature (2020) 588:277-283). Thus, when centromere sizes are reduced, they may have a much decreased tendency for bipolar attachment to the karyokinetic spindle during meiotic divisions, thereby reducing the likelihood of misdivision. Generally in the literature, it was hypothesized by some groups that the misdivision frequency of individual chromosomes in wheat may be directly proportional to the size of the centromeres (Kopecky & Lukaszewski, Misdivision of telocentrics and isochromosomes in wheat, Cytogenetic and Genome Research (2019) 157:179-188); i.e., smaller centromeres undergo misdivision less frequently, yet this theoretical knowledge about centromere architecture was so far not comprehensively exploited as part of complex breeding studies. The term rearrangement or re-arrangement or re-arranged / rearranged as used herein refers to a genomic rearrangement that is the result of an intra-chromosomal re- arrangement, i.e., typically involving only one chromosome material that is re-shuffled and functionally re-assembled, not to an inter-chromosomal rearrangement involving different chromosomes (e.g., inter-chromosomal translocations). A re-arrangement may inter alia result in a reduced size of centromers of the engineered and re-arranged alien addition chromosome in comparison to the ancestor chromosome it originates from. Accordingly, this may further ensure greater stability and reliability in the maintenance of the desired genetic traits. Generally, the alien addition chromosome architecture as disclosed and claimed herein, and particularly the presence of the central chromosomal unit around the centromeric region, significantly enhances the stability and effectiveness of the 42+1 chromosome system, providing a practical and scalable solution for hybrid cereal production. Addressing the needs of an improved hybrid cereal line, a first aspect relates to a cereal plant comprising an engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes, wherein the set of genes comprises at least one gene cluster and / or at least one individual gene contributing to a color phenotype in the cereal plant, preferably seed coloring, (i) wherein the engineered alien addition chromosome has a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes; and / or (ii) wherein the male fertility restorer gene and the set of genes are independently located within 40%, preferably within 30%, more preferably within 20% relative distance to the centromere or centromeric region of the engineered alien addition chromosome; and / or (iii) wherein the male fertility restorer gene is located on the same chromosomal arm with at least one gene cluster and / or at least one individual gene contributing to the color phenotype; and / or wherein at least one gene cluster and / or at least one individual gene contributing to the color phenotype is located on a different chromosome arm than the male fertility restorer gene. The probability that a gene undergoes recombination increases with its relative distance from the centromere; genes positioned proximal to the centromere show strong crossover suppression (Saintenac et al., Detailed recombination studies along chromosome 3B provide new insights on crossover distribution in wheat (Triticum aestivum L.), Genetics (2009) 181:393–403). On chromosome 3B, for example, ~90% of crossovers occur within the distal ~40% of the chromosome (Saintenac et al., Genetics (2009) 181:393–403), and fine-scale mapping further shows ~82% of crossovers confined to the distal ~19% (Darrier et al., High-Resolution Mapping of Crossover Events in the Hexaploid Wheat Genome Suggests a Universal Recombination Mechanism, Genetics (2017) 206(3):1373–1388). Therefore, positioning the male fertility restorer gene and the associated gene set within 30%, preferably within 20%, of relative distance to the centromere or centromeric region of the engineered alien addition chromosome is advantageous because these centromere- proximal regions are strongly recombination-suppressed in wheat. This suppression minimizes the risk of genetic reshuffling during breeding, thereby stabilizing the integrity of the fertility restorer function and linked genetic elements across generations. In practical terms, such positioning ensures durable inheritance, reduced linkage breakage, and greater predictability of trait expression. Relative distance to the centromere or centromeric region means the distance on each arm of the chromosome to the centromere, or in certain embodiments a centromeric region, which can be determined as physical distance (in Mb) or as genetic distance. The skilled person is well aware of the fact that a precise position of a centromere requires the availability of cytology, centromere mapping and / or sequencing and assembly data. As long as the data are not confirmed by several technologies and no exact dimensions of a centromere, yet rough dimensions are available, the term “centromeric region” is thus used herein to define the position of the centromere. The “relative distance to the centromere or centromeric region” thus implies the distance, preferably the physical distance, from an element to the middle of the known or calculated centromere or centromeric region. A cereal plant may be a crop plant of the grass family (i.e., Graminaceae or Poaceae) cultivated for the food value of their grains, such as, but not limited to, wheat, triticale, corn, rice, barley, oat, rye, sorghum, millet, buckwheat, fonio, and quinoa. In certain embodiments the cereal plant is a diploid wheat, tetraploid wheat, hexaploid wheat, triticale, maize, rice, barley, or oats. In certain embodiments, the cereal plant is wheat, e.g., any species of the genus Triticum, including progenitors thereof, as well as progeny thereof produced by crosses with other species. In certain embodiments, the cereal plant is a tetraploid wheat or a hexaploid wheat. Hexaploid wheat (e.g., genome organization of AABBDD), comprised of 42 chromosomes, and includes, for example, T. aestivum, T. spelta, T. mocha, T.compactum, T. sphaerococcum, T. vavilovii, and interspecies cross thereof. Tetraploid wheat (e.g., genome organization of AABB), comprised of 28 chromosomes, and includes, for example, T. durum (also referred to as durum wheat or T. turgidum ssp. durum), T. dicoccoides, T. dicoccum, T polonicum, and interspecies cross thereof. Wheat can also include possible progenitors of hexaploid or tetraploid Triticum sp. such as T. uartu, T. monococcum or T. boeoticum for the A genome, Aegilops speltoides for the B genome, and T. tauschii (also known as Ae. or Ae. tauschii) for the D genome. In certain embodiments, the cereal plant is a Triticum durum or Triticum aestivum. Additional exemplary plants for use with the invented methods and compositions include, but not limited thereof, Hordeum vulgare, H. bulbusom, Sorghum bicolor, Saccharum officinarium, Zea mays, Setaria italica, Oryza minuta, O. sativa, O. australiensis, O. alta, Triticum aestivum, Triticum durum, Triticale, Malus domestica, Brachypodium distachyon, Hordeum marinum, Aegilops tauschii, Daucus glochidiatus, Beta vulgaris, Daucus pusillus, Daucus muricatus, Daucus carota, Eucalyptus grandis, Nicotiana sylvestris, Nicotiana tomentosiformis, Nicotiana tabacum, Nicotiana benthamiana, Solanum lycopersicum, Solanum tuberosum, Coffea canephora, Vitis vinifera, Erythrante guttata, Genlisea aurea, Cucumis sativus, Morus notabilis, Arabidopsis arenosa, Arabidopsis lyrata, Arabidopsis thaliana, Crucihimalaya himalaica, Crucihimalaya wallichii, Cardamine flexuosa, Lepidium virginicum, Capsella bursa pastoris, Olmarabidopsis pumila, Arabis hirsute, Brassica oleracea, Brassica rapa, Raphanus sativus, Brassica juncacea, Brassica nigra, Eruca vesicaria subsp. sativa, Citrus sinensis, Jatropha curcas,Populus trichocarpa, Medicago truncatula, Cicer yamashitae, Cicer bijugum, Cicer arietinum, Cicer reticulatum, Cicer judaicum, Cajanus cajanifolius, Cajanus scarabaeoides, Phaseolus vulgaris, Glycine max, Gossypium sp., Astragalus sinicus, Lotus japonicas, Torenia fournieri, Allium cepa, Allium fistulosum, Allium sativum, Helianthus annuus, Helianthus tuberosus and Allium tuberosum, or any variety or subspecies belonging to one of the aforementioned plants. According to another embodiment of the various aspects disclosed herein, the plants, cells, tissues, organ, materials, part of plants and seeds thereof are not obtained by or obtainable by an essentially biological process. Similarly, in certain embodiments of the methods disclosed herein according to the various aspects and embodiments disclosed herein, the methods are not relying on an essentially biological process, or will not rely on an essentially biological process step. In certain embodiments the cereal plant may be produced by conventional techniques using Triticum sp. as a parent in a sexual cross with a non-Triticum species, such as rye (Secale cereal), including but not limited to triticale. In certain embodiments, the cereal plant is a triticale. In certain embodiments, the male fertility restorer gene and the set of genes may be located on different chromosome arms. The engineered alien chromosome may be designed to exhibit a reduced rate of misdivision relative to a non-engineered chromosome. This reduction may be achieved through structural modifications, such as a reduced centromere size and / or the increased proximity of the male fertility restorer gene and the set of genes to the centromere, as shown in the exemplary embodiment of FIG 6. In certain embodiments, the male fertility restorer gene and the set of genes may be located on the same chromosome arm. Advantageously, although misdivision may still occur, this strategy would prevent the production of unmarked fertile seeds. Such a rearrangement within the alien addition chromosome could be accomplished through the application of gametocidal (Gc) genes, irradiation, genome editing and / or mutagenesis techniques known in the art. In certain embodiments, the engineered alien addition chromosomes, or relevant parts of said chromosome, can be introduced into a cell, tissue, organ, material, seed of a cereal plant, preferably a wheat plant. To stabilize the 42+1 chromosome system it is crucial to prevent misdivision of the alien addition chromosome, which currently results in the production of unmarked (e.g., white- colored) fertile seeds and, to a lesser extent, plants derived from marked (e.g., blue- colored) male sterile seeds. This can be addressed by rearranging the monosomic alien addition chromosome to position the male fertility restoration gene in close association with the set of genes on a single chromosome arm or in closer proximity to each other, eventually distributed over two chromosome arms. While misdivision may still occur this rearrangement would prevent the emergence of unmarked fertile seeds. The internal rearrangement of the alien addition chromosome can be achieved through the application of gametocidal (Gc) genes, irradiation, and / or genome editing techniques. In certain embodiments, in comparison to the original chromosome architecture (cf. FIG 3A ), the engineered alien addition chromosome (cf. FIG 3B) may comprise an architecture, where markers G, D, J, and F, are retained, while, for example, A, B, and Hare lost. Marker C, E, and K are suitable for screening both chromosomes. In other embodiments, at least markers G, D, J and F will be retained on the engineered alien addition chromosome and / or at least markers A, B, C and H are lost on the engineered alien addition chromosome in comparison to the original chromosome architecture. Wherein a marker or primers specific for the MYB_618 gene will be usually present on the original chromosome, in certain embodiments, a marker or primers specific for the MYB_618 gene may be lost on the engineered alien addition chromosome in comparison to the original chromosome architecture. In certain embodiments according to the various aspects and embodiments as disclosed herein related to a cereal plant or a chromosomal unit and the associated methods, MYB_618 as present on the original BLA chromosome may not be present on the re-arranged alien addition chromosome, or MYB_618 may be present in inactive or truncated form. A hybrid system could be developed by integrating the alien addition chromosome into the 42-chromosome genome of the cereal plant, resulting in a system with similar characteristics. In this approach, the set of genes would be linked to the male fertility restoration gene and incorporated into the existing 42 chromosomes. This translocation could be facilitated by homoeologous pairing (e.g., ph1b-assisted) and / or genome editing methods. In polyploid organisms, the presence of multiple similar chromosomes from different species (homoeologous chromosomes) could potentially lead to improper pairing and recombination, which might result in genetic instability or sterility. However, most polyploid plants have evolved mechanisms to ensure that only homologous chromosomes pair during meiosis, effectively suppressing homoeologous pairing. Wheat, for example, has specific genes that suppress homoeologous pairing during meiosis to maintain genomic stability. Two key genes involved in this process are Ph1 (Pairing homoeologous 1) and Ph2 (Pairing homoeologous 2). These genes prevent homoeologous chromosomes from pairing, ensuring that only homologous chromosomes undergo recombination. Mutations in these suppressor genes, such as ph1b and ph2, reduce their ability to prevent homoeologous pairing (Koo et al., Homoeologous Recombination: A Novel and Efficient System for Broadening the Genetic Variability in Wheat, Agronomy (2020), 10, 8, 1059). In the case of the ph1b mutation, the suppression of homoeologous pairing is weakened, allowing chromosomes from different genomes or species to pair and recombine during meiosis. This can be particularly useful in breeding programs where the introduction of genetic material from wild relatives or other species is desired, as it facilitates the transfer of beneficial traits into cultivated varieties. In certain very specific embodiments the cereal plant comprises at least one homoeologous chromosome pair, wherein the pair consisting of a first and second chromosome, the first chromosome is native to the cereal plant and the second chromosome comprises an engineered alien chromosome or a fragment thereof, comprising a male fertility restorer gene and a set of genes contributing to a color phenotype, wherein the cereal plant comprises a male fertility gene mutation causing male sterility. In certain embodiments the cereal plant may comprise a mutated or deleted homoeologous pairing suppressor gene. In certain embodiments the cereal plant may comprise the mutated homoeologous pairing suppressor gene ph1b and / or ph2. In certain embodiments, the color phenotype is blue seed coloration, conferred by the expression of a blue aleurone locus or a cluster of genes involved in anthocyanin biosynthesis. In certain embodiments, the set of genes is organized as a three-gene cluster comprising nucleic acid sequences encoding MYB480, MYC480, and F35H480. In certain embodiments, the set of genes further comprises a nucleic acid sequence encoding MYC616. One embodiment relates to the cereal plant wherein the at least one gene cluster contributing to the color phenotype is located on the short arm of the engineered alien addition chromosome and the male fertility restorer gene is located on the long arm of the engineered alien addition chromosome. One embodiment relates to the cereal plant, wherein the at least one individual gene contributing to the color phenotype and the male fertility restorer gene are on the same arm of the engineered alien addition chromosome. One embodiment relates to the cereal plant, wherein the set of genes comprises or consists of F35H480, MYC480, MYB480 and / or MYC616, wherein F35H480, MYC480, MYB480 form a gene cluster, being defined by the sequences as set forth in the embodiment following the sixth aspect, (vii) to (xii). A second aspect relates to a chromosomal unit comprising the set of genes defined in the first aspect or any embodiment thereof and the male fertility restorer gene as defined in the first aspect or any embodiment thereof, wherein said genes are located within a genomic interval, the interval spanning from the gene cluster as defined in the previous embodiment to MYC616 as defined in the previous embodiment and comprising in-between the gene cluster and MYC616 the male fertility restorer gene as defined in any of the previous embodiment. The chromosomal unit is characterized by the interval in-between the gene cluster of MBY / MYC / F35H as shown in FIG 3B on the short arm of the re-arranged chromosome and MYC616 on the long arm, with a centromeric region and the fertility restore gene in-between. The chromosomal unit can be screened for and / or identified using markers and primers further disclosed herein. Preferably, the chromosomal unit is arranged as and / or obtainable from seeds deposited under accession number NCIMB 44423. The gene cluster marking the limit of the chromosomal unit will comprise one, preferably two, more preferably three genes of a set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, the chromosomal unit is characterized by a strong genetic linkage between the set of genes and the male fertility restorer gene, resulting in a separation or misdivision rate between them of ≤ 1%, preferably ≤ 0.5%, more preferably ≤ 0.2% as observable by a color screening of the seeds as detailed below. In certain embodiments, the chromosomal unit is located on a rearranged, engineered alien addition chromosome, which exhibits a significantly reduced likelihood of misdivision compared to a non-rearranged chromosome. In certain embodiments, the chromosomal unit is located on the GC8.2 chromosome and is the result of a chromosomal rearrangement induced by the activity of a gametocidal (Gc) gene, which repositions the constituent genes to ensure their co-inheritance. In certain embodiments, within the chromosomal unit, the gene cluster is located on the short arm of the chromosome in close proximity to the centromere, while the male fertility restorer gene and the MYC616 gene are located on the long arm, also in close proximity to the centromere. In certain embodiments, the chromosomal unit functionally ensures that the color phenotype, preferably blue seed coloration, is a reliable indicator of the presence of the male fertility restorer gene, thereby facilitating the accurate selection of male-sterile female seeds. In certain embodiments, the genomic interval defining the chromosomal unit can be identified and tracked using molecular markers specific to the gene cluster and the MYC616 gene. In certain embodiments, the chromosomal unit resides on a monosomic alien addition chromosome within the genome of a cereal plant. One embodiment relates to the cereal plant, wherein the cereal plant comprises, preferably homozygously, a male fertility gene mutation, which is a gene deletion, a gene knockdown, or a gene knockout, preferably wherein the male fertility gene is Ms1 or a nucleic acid as defined comprising a nucleic acid sequence independently selected from the group consisting of: (i) a nucleic acid as set forth in SEQ ID NO: 47, 50, 54 or 57; (ii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 47, 50, 54 or 57; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 48, 51, 55, or 58; (iv) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 48, 51, 55 or 58; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59. The cereal plant may comprise nucleic acids and peptides that regulate male fertility. In certain embodiments, these nucleic acids correspond to male fertility genes that are endogenous or "native" to the cereal plant. In certain embodiments, the male fertility gene is subject to mutation, resulting in a male-sterile phenotype in the cereal plant. Mutations that suppress gene function can occur through various mechanisms, including, but not limited to, the deletion or insertion of one or a few nucleotides within the gene's nucleotide sequence (e.g., within the promoter, coding sequence, or intron), substitution of one or a few nucleotides with different nucleotides, or complete gene knockout (e.g., by homologous recombination using an appropriate targeting vector). Cereal plants with mutations in both alleles of the gene can be produced using conventional breeding techniques, as known in the art. In certain embodiments, the mutation may result from gene deletion, gene knockdown, or gene knockout. In certain embodiments the Ms1 mutant is ms1d, ms1e, and ms1f, or a variation thereof, (Klindworth et al. Chromosomal Location of Genetic Male Sterility Genes in Four Mutants of Hexaploid Wheat, Crop Sci. (2002), 42:1447-1450). In certain embodiments, the mutation is the Probus deletion (ms1b) (Tucker et al., Molecular identification of the wheat male fertility gene Ms1 and its prospects for hybrid breeding, Nature Communications (2017), 8, 869). One embodiment relates to the cereal plant, wherein the cereal plant comprises one additional chromosome to its euploid number of chromosomes, wherein the male fertility restorer gene and the set of genes are on the additional chromosome. One embodiment relates to the cereal plant, wherein the cereal plant is a tetraploid wheat, hexaploid wheat, diploid wheat, or triticale. A third aspect relates to a cell, a seed, or a progeny or part thereof of the cereal plant, or the chromosomal unit. "Progeny” in the context of the plants as discussed herein include an F1 cereal plant produced from the cross of two cereal plants where at least one cereal plant includes a wheat line, variety, or cultivar represented by a sample of seeds which have been deposited under the terms of the Budapest Treaty as NCIMB 44423, or crossed therewith, and progeny further includes, but is not limited to, subsequent F2, F3, F4, F5, F6, F7, F8, F9, and F10 generational crosses with the recurrent parental line. A fourth aspect relates to a method for selecting and / or sorting of at least one male-sterile female seed of a cereal plant comprising the steps of: (i) separating, preferably automatically separating, from the progeny according to the previous aspect a colored seed from an normal seed, wherein the at least one normal seed is male-sterile; and (ii) obtaining a cereal plant, including a hybrid cereal plant, a part of a cereal plant, a progeny thereof, a cell and / or a seed thereof. A fifth aspect relates to a method of generating a color-coded male sterile system for phenotypic and / or genetic selection of a cereal plant comprising: a) selecting a cereal plant line comprising a male fertility gene mutation, preferably wherein the male fertility gene mutation is homozygous, wherein the cereal plant line comprises at least one engineered alien addition chromosome carrying a male fertility restorer gene, and a set of genes, or wherein the cereal line comprises a chromosome comprising a chromosomal unit as defined in the second aspect; and b) optionally: rearranging the at least one engineered alien addition chromosome, wherein the rearranging step comprises using the presence of a gametocidal gene which induces breakage and rearrangement of the at least one engineered alien addition chromosome, to the cereal plant line of step a), wherein the gametocidal gene is located on a monosomic or a disomic gametocidal addition chromosome; and / or c) optionally: applying mutagenesis to at least one cell, seed, plant or part of a plant of the cereal plant line of step a), wherein mutagenesis is selected from genome editing, chemical and radiation induced mutagenesis, or a combination thereof; and (d) obtaining a cereal plant comprising a rearranged engineered alien addition chromosome. The method of generating a color-coded male sterile system for subsequent genomic and / or genetic selection of cereal plants may comprise irradiating a male-sterile female plant that possesses an alien addition chromosome carrying a male fertility restorer gene and a set of genes located on opposite sides of the centromere on one and the same arm of one chromosomal arm, or located on different arms of a chromosome, and subsequently testing for rearrangement of the alien addition chromosome. In specific embodiments, the method comprises the following steps: a) Selecting a cereal plant line homozygous for a mutation in the male fertility gene, where the line includes at least one engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes on opposite sides of the centromere; b) Inducing rearrangement of the engineered alien addition chromosome; and c) Obtaining a cereal plant with the rearranged engineered alien addition chromosome. The details of the male fertility gene, the male fertility restorer gene, and the set of genes are provided above. In certain embodiments, the rearrangement in step b) may be achieved through the irradiation of seeds from the cereal plant line selected in step a). Irradiation may induce chromosomal rearrangement of at least one alien addition chromosome, resulting in the desired gene configuration. Radiation treatment can be applied at various developmental stages of the seed. In some embodiments the seeds are irradiated prior to germination. The types of radiation suitable for inducing chromosome breakage and rearrangement include, but are not limited to, X- rays, fast neutrons, gamma rays, ultraviolet light, mixed high-energy particles, and ion beams. The selection of a specific radiation treatment is dependent on the material being treated and the desired frequency and spectrum of mutations. For example, fast neutrons can induce relatively small segment deletions or translocations, while X-rays and gamma rays offer good penetration, high reproducibility, high translocation frequency, and fewer issues related to the disposal of radioactive waste. The method of generating a color-coded male sterile system for genomic selection of cereal plants may comprise the use of genome editing techniques to insert a male fertility restorer gene, with the optional inclusion of the set of genes. In certain embodiments, the method involves the integration of a male fertility restorer gene and, optionally, the set of genes into either the wheat genome or an alien addition chromosome within a cereal plant. The integration may occur either randomly or in a targeted manner. In specific embodiments, the method includes the following steps: a) Selecting a cereal plant line that is homozygous for a mutation in the male fertility gene; b) Integrating a male fertility restorer gene, and optionally the set of genes, into the genome or alien addition chromosome of the cereal plant line, with the male fertility restorer gene and the set of genes being genetically linked and positioned in close proximity; and c) Obtaining a cereal plant that contains the genetically linked male fertility restorer gene and the set of genes. Advantageously, this approach allows for the precise or random incorporation of essential genetic elements into the plant genome, enabling the establishment of male fertility linked to seed coloration. In certain embodiments genome editing comprises A) inserting the same or a different male fertility restorer gene on the same side of the centromere of the at least one engineered alien addition chromosome as the set of genes, wherein inserting comprises introducing into a cell of the cereal plant line of step a) a gene cassette carrying the same or different male fertility restorer gene and a site-directed nuclease designed to make a double-strand break at a target site in the cereal plant line genome on the same side of the centromere of the at least one engineered alien addition chromosome as the set of genes and wherein the same or different male fertility restorer gene is integrated into the cereal plant line genome at the site of the double-strand break; or B) introducing at least two different site- directed nucleases into a cell of the cereal plant line of step a), wherein at least one site- directed nuclease makes a first double strand break close to the set of genes but between the set of genes and the end of the engineered alien addition chromosome to create a first end of the chromosome and at least one other site-directed nuclease makes a second double strand break close to the male fertility restorer gene but between the male fertility restorer gene and the centromere of the engineered alien addition chromosome to create a second chromosome end, and wherein the chromosome ends are swapped so that the set of genes is on the same arm of the at least one engineered alien addition chromosome as the male fertility restorer gene; C) introducing at least two different site-directed nucleases into a cell of the cereal plant line of step a), wherein at least one site-directed nuclease makes a first double strand break close to the male fertility restorer gene but between the male fertility restorer gene and the end of the engineered alien addition chromosome to create a first end of the chromosome and at least one other site-directed nuclease makes a second double strand break close to the set of genes but between the set of genes and the centromere of the engineered alien addition chromosome to create a second chromosome end, and wherein the chromosomes ends are swapped so that the set of genes is on the same arm of the at least one engineered alien addition chromosome as the male fertility restorer gene. These methods may work in all species which are self-fertilized. Additional plants can be used, including monocot and dicot plants. Examples of monocot plants that can be used include, but are not limited to, sugarcane (Saccharum spp.), corn (Zea mays), rice (Oryza sativa), rye (Secale cereale), sorghum (Sorghum bicolor, Sorghum vulgare), millet (e.g., pearl millet (Pennisetum glaucum), proso millet (Panicum miliaceum), foxtail millet (Setaria italica), finger millet (Eleusine coracana)), oats (Avena), barley (Hordeum), switchgrass (Panicum virgatum), pineapple (Ananas comosus), banana (Musa spp.), palm, ornamentals, turfgrasses, and other grasses. Examples of dicot plants that can be used include, but are not limited to, soybean (Glycine max), canola (Brassica napus and B. campestris), alfalfa (Medicago sativa), tobacco (Nicotiana tabacum), Arabidopsis (Arabidopsis thaliana), sunflower (Helianthus annuus), sugar beet (Beta vulgaris), cotton (Gossypium arboreum), and peanut (Arachis hypogaea), tomato (Solanum lycopersicum), potato (Solanum tuberosum), etc. Additional monocots that can be used include oil palm (Elaeis guineensis), sudangrass (Sorghum × drummondii), and rye (Secale cereale). Additional dicots that can be used include safflower (Carthamus tinctorius), coffee (Coffea arabica and Coffea canephora), amaranth (Amaranthus spp.), and rapeseed (Brassica napus and Brassica napobrassica; high erucic acid and canola). One embodiment relates to the wherein the engineered alien addition chromosome is monosomic. In certain embodiments, the cereal plant may comprise at least two engineered alien additional chromosomes, arranged as a pair (i.e., disomic alien addition chromosomes), in addition to its euploid number of chromosomes, wherein the male fertility restorer gene and the set of genes are located on at least one of the engineered alien additional chromosomes. One embodiment relates to the method, wherein the gametocidal gene is introduced as a monosomic addition chromosome, and / or the gametocidal gene is the gametocidal factor located on chromosome 4Mgof Aegilops geniculate or 2Ccof Aegilops cylindrica. Gametocidal (Gc) genes, also known as Cuckoo genes, are known to cause gamete abortion and chromosome breakage. In certain embodiments, the alien addition chromosome containing cereal plant as disclosed herein can be generated by the Gc gene approach. In certain embodiments, the Gc gene induces breakage and rearrangement of at least one alien addition chromosome. In certain embodiments, the method comprises the following steps: a) selecting a cereal plant line comprising a male fertility gene mutation, preferably wherein the male fertility gene mutation is homozygous, wherein the cereal plant line comprises at least one engineered alien addition chromosome carrying a male fertility restorer gene as defined in the first aspect; and (b) optionally: rearranging the at least one engineered alien addition chromosome, wherein the rearranging step comprises using the presence of a gametocidal gene which induces breakage and rearrangement of the at least one engineered alien addition chromosome, to the cereal plant line of step a), wherein the gametocidal gene is located on a monosomic or a disomic gametocidal addition chromosome; and / or (c) optionally: applying mutagenesis to at least one cell, seed, plant or part of a plant of the cereal plant line of step a), wherein mutagenesis is selected from genome editing, chemical and radiation induced mutagenesis, or a combination thereof; and (d) obtaining a cereal plant comprising a rearranged engineered alien addition chromosome as defined in the first aspect. The Gc gene can be introduced into the cereal plant line as a monosomic addition chromosome. In certain embodiments, the Gc gene is later removed from the cereal plant line. This can be achieved by discarding seeds that express the Gc gene. Detection of the Gc gene can be performed using molecular and / or cytogenetic techniques well known to those skilled in the art. In certain embodiments, the Gc gene is already present in the genome of the cereal plant. Once the rearrangement of the alien addition chromosome has occurred, the Gc gene may be optionally mutated or inactivated. In certain embodiments, the cereal plant comprises at least one Gc gene. In certain embodiments the Gc genes are derived from the Aegilops genus. In certain embodiments, the Gc gene are derived from different genomes such as, but not limited to, C, S, Sl, Sshand Mg. (Endo, The gametocidal chromosome as a tool for chromosome manipulation in wheat, Chromosome Res. (2007), 15(1):67-75). In certain embodiments, the Gc gene is a Gc factor located on chromosome 4Mgof Ae. geniculata (Kynast et al., Fate of Multicentric and Ring Chromosomes Induced by a New Gametocidal Factor Located on Chromosome 4Mg of Aegilops geniculata, Chromosome Res. (2000), 8:133-139); on chromosome 2Ccof Ae. cylindrica; on chromosomes 3C of Ae. caudata and / or 3Ctof Ae. triuncialis; on chromosome 2S and / or 4S of Ae. longissimi; or Gc2 of Ae. sharonensis (Maan, Exclusive preferential transmission of an alien chromosome in common wheat, Crop Sci. (1975),15:287-292; Endo, Gametocidal chromosomes and their induction of chromosome mutations in wheat, Jpn. J. Genet. (1985), 60: 125-135). In certain embodiments, the Gc gene is a Gc factor located on 4Mg of Ae. geniculata or 2Ccof Ae. cylindrical). One embodiment relates to the method, wherein the method additionally comprises (x) screening for and / or for identifying the presence of the engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes, and (y) selecting and / or sorting the at least one seed according to the third aspect based on a color phenotype in the cereal plant contributed by the activity of the set of genes as defined in the first aspect or any embodiment thereof. One embodiment relates to the cereal plant, wherein the engineered alien addition chromosome is additionally modified by mutagenesis and / or genetic engineering, wherein mutagenesis includes chemical mutagenesis, radiation mutagenesis, and genome editing, wherein genome editing includes editing by site-directed nucleases, including zinc-finger nuclease (ZFNs) systems, transcription activator-like effector nuclease (TALENs) systems, meganuclease systems and CRISPR / Cas systems. According to the embodiments as disclosed herein, site-directed and random mutagenesis are thus encompassed by the term mutagenesis. The altered expression of the gene or genes can be achieved by mutagenesis, TILLING, or genetic engineering. Identification and selection of plants comprising genes with an altered expression can be performed using marker-assisted selection using random or functional DNA markers based on the sequence and the position information provided herein. In one embodiment, genome editing may be performed with the at least one genome editing system is selected from a CRISPR / Cas system, preferably from a CRISPR / MAD7 system, a CRISPR / Cpf1 (CRISPR / Cas12a) system, a CRISPR / MAD2 system, a CRISPR / Cas9 system, a CRISPR / CasX system, a CRISPR / CasY system, a CRISPR / Cas13 system, a CRISPR / Cas12 system, a CRISPR / CasPhi system, or a CRISPR / Csm system, always including a cognate guide RNA system, or the at least one genome editing system is selected from a zinc finger nuclease system, or a transcription activator-like nuclease system, or a meganuclease system, or any combination, variant, or an active fragment thereof. A sixth aspect relates to an engineered alien addition chromosome, including an isolated engineered alien addition chromosome. In certain embodiments the engineered alien addition chromosome carries the male fertility restorer gene and a set of genes, wherein the set of genes comprises the at least one gene cluster and / or the at least one individual gene contributing to a color phenotype. In certain embodiments the engineered alien addition chromosome has a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2%. In certain embodiments the engineered alien addition chromosome has the male fertility restorer gene and the set of genes contributing to a color phenotype located within 40%, preferably within 30%, more preferably within 20% relative distance to its centromere. In certain embodiments the engineered alien addition chromosome carries the male fertility restorer gene and at least one gene or gene cluster for a color phenotype on a first chromosomal arm, and also carries at least one further gene or gene cluster for a color phenotype on a second, different chromosomal arm. In certain embodiments the engineered alien addition chromosome carries a gene cluster contributing to a color phenotype on its short arm and a male fertility restorer gene on its long arm. In certain embodiments the engineered alien addition chromosome carries a set of gene contributing to a color phenotype and a male fertility restorer gene on the same chromosome arm. In certain embodiments, an engineered alien addition chromosome carries a set of genes comprising or consisting of F35H480, MYC480, MYB480, and / or MYC616, wherein F35H480, MYC480, and MYB480 form a gene cluster. In certain embodiments the engineered alien addition chromosome is suitable for restoring male fertility in a cereal plant that comprises a male fertility gene mutation, preferably a homozygous deletion of the Ms1 gene, or any kind of knock-down, downregulation or (partial) knock-out. In certain embodiments the engineered alien addition chromosome is suitable for use as a monosomic addition in a cereal plant, such as a diploid wheat, tetraploid wheat, hexaploid wheat, or triticale. In certain embodiments the engineered alien addition chromosome comprises a chromosomal unit, said unit comprising a set of genes and a male fertility restorer gene located within a genomic interval on the chromosome, the interval spanning from a gene cluster to a MYC616 gene. In certain embodiments the engineered alien addition chromosome comprises a chromosomal unit that exhibits a separation or misdivision rate between its constituent genes of ≤ 1%, preferably ≤ 0.5%, more preferably ≤ 0.2%. In certain embodiments the engineered alien addition chromosome is an acrocentric chromosome resulting from a genomic rearrangement, which exhibits a significantly reduced likelihood of misdivision (e.g., to be determined by the convenient phenotypic color screening of the seeds) compared to a non-rearranged progenitor chromosome. In certain embodiments the engineered alien addition chromosome, known as the GC8.2 chromosome, comprises a chromosomal unit wherein a gene cluster is located on the short arm and the male fertility restorer gene and a MYC616 gene are located on the long arm, preferably with all components being in close proximity to the centromere. In certain embodiments the engineered alien addition chromosome is provided in an isolated form. In certain embodiments the engineered alien addition chromosome is the GC8.2 chromosome. In certain embodiments the engineered alien addition chromosome is obtainable from the seed of the wheat line GC8.2 / KWS0484, deposited with the NCIMB under accession number 44423. In certain embodiments the engineered alien addition chromosome is the product of a rearrangement induced by a gametocidal (Gc) gene, by irradiation, or by a genome editing technology. In certain embodiments the engineered alien addition chromosome is used as a template for nucleic acid sequencing, for fluorescence in situ hybridization (FISH) analysis, or for the development of specific molecular markers. In certain embodiments, an engineered alien addition chromosome as described herein may be physically isolated from the host plant genome to enable subsequent molecular or cytogenetic analyses, including but not limited to sequencing, probe development, or marker identification. The isolation may be carried out using any of a variety of techniques known in the art for preparing and separating chromosomes from plant cells. In general, actively dividing plant material, such as meristematic tissues, may be harvested, and the cells therein optionally subjected to a cell cycle synchronization or mitotic arrest treatment so as to enrich for cells in a stage of division in which the chromosomes are condensed and morphologically distinct. The plant cell walls may then be disrupted or removed, for example by mechanical, chemical, or enzymatic means, to facilitate the release of chromosomes. The chromosomes may be liberated from such cells or protoplasts using any suitable lysis procedure and maintained in a stabilizing medium that preserves their structural integrity. The chromosomes may be visualized, identified, or distinguished using one or more labeling or detection strategies. Such strategies may include the use of general DNA- binding fluorochromes, base-specific dyes, labeled DNA or RNA probes, antibodies, or other affinity reagents directed to unique sequences or chromosomal features. Combinations of such labels may be employed to enable discrimination of a particular alien addition chromosome from other chromosomes present in the preparation. For enrichment or purification, the chromosome preparation may be subjected to a physical separation process. Suitable techniques include, but not limited to,, flow cytometry with sorting, microdissection, micromanipulation, pulsed-field electrophoretic methods, or other cytogenetic or microfluidic techniques capable of separating individual chromosomes or populations of chromosomes. Where flow cytometric methods are employed, the labeled chromosome suspension is passed through a flow instrument, and chromosomes of interest are identified on the basis of their optical or fluorescence characteristics and collected into a separate fraction. Following isolation, the identity and purity of the isolated chromosome may be confirmed by molecular or cytogenetic assays, including but not limited to PCR amplification of diagnostic markers, hybridization with chromosome-specific probes, or sequencing. One embodiment relates to the cereal plant, or the chromosomal unit, or the engineered alien addition chromosome, wherein the male fertility restorer gene comprises a nucleic acid sequence selected from the group consisting of: (i) a nucleic acid sequence as set forth in SEQ ID NO: 1; (ii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 1; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 2; (iv) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 2; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 3; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 3; and / or wherein the set of genes comprises a nucleic acid sequence independently selected from the group consisting of: (vii) a nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (viii) a nucleic acid sequence with at least 80% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (ix) a nucleic acid sequence having a coding sequence of SEQ ID NO: 5, 8, 11 and / or 14; (x) a nucleic acid sequence having a coding sequence with at least 80% sequence identity to the nucleic acid sequence of SEQ ID NO: 5, 8, 11 and / or 14; (xi) a nucleic acid sequence encoding an amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15; and (xii) a nucleic acid sequence encoding an amino acid sequence with at least 80% sequence identity to the amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15. According to the present invention a male fertility restorer gene may be used to restore the fertility of a male-sterile plant. The male fertility restorer gene is selected to be able to compensate for the mutation of the male-fertility gene or to counteract any gene activity that is or encodes a sterility gene or protein activity. In certain embodiments, the male fertility restorer genes are recessive. In certain embodiments, the male fertility restorer genes are dominant. The male fertility restorer gene can be a functional version of the male fertility genes disclosed above (cf. respective SEQ ID NOs). In certain embodiments, the male fertility restorer gene is Ms1, including homologs and orthologs of Ms1. In certain embodiments the male fertility restorer gene is from Triticum boeoticum, T. monococcum, T. thaouder, or T. urartu. In certain embodiments, the male fertility restorer gene may be identical to the native male fertility gene of the cereal plant. In certain embodiments, the male fertility restorer gene may be orthologous to the native male fertility gene of the cereal plant. In certain embodiments, the male fertility restorer gene may be located at an orthologous position on the alien addition chromosome, corresponding to the location of the native male fertility gene within the genome of the cereal plant (i.e., the male fertility restorer gene is positioned in the same or a similar genomic location on the alien addition chromosome as the native male fertility gene in the cereal plant genome). The set of genes may contribute to a color phenotype in the cereal plant and can be used to identify male-fertile cereal plants and / or seeds and discriminate them from male-sterile plants and / or seeds. To accurately identify male-fertile plants, the set of genes may be genetically linked and / or comprised on a chromosomal unit with the male fertility restorer gene. In certain embodiments, the set of genes contributes to a color phenotype in seeds in a stable manner. This stability is a direct functional consequence of the genetic interlinking and structural organization of the genes on the engineered alien addition chromosome, which ensures their reliable co-inheritance with the male fertility restorer gene. In certain embodiments the set of genes comprises of a three-gene cluster including: a) a nucleic acid sequence encoding MYB480; b) a nucleic acid sequence encoding MYC480; and c) a nucleic acid sequence encoding F35H480. In certain embodiments the set of genes further comprises of a nucleic acid sequence encoding MYC616 and a set of genes, including a three-gene cluster, or a subset thereof. In certain embodiments the set of genes comprises at least one nucleic acid sequence selected from the group consisting of: a) a nucleic acid sequence encoding MYB480; b) a nucleic acid sequence encoding MYC480; c) a nucleic acid sequence encoding F35H480; and d) a nucleic acid sequence encoding MYC616. In certain embodiments, the expression of the set of genes results in a blue pigmentation in specific tissues of the cereal plant, such as the aleurone layer of the seed. This blue coloring serves as a visual marker, allowing for the identification and selection of plants or seeds that carry the associated genetic traits, such as male fertility restoration. The ability to directly sort the seeds of the male-sterile female line from based on seed coloration offers a significant advantage by streamlining the process and substantially reducing the production costs of hybrid seeds. This system allows for efficient and accurate separation of seeds based on color, where a seed sorter can easily distinguish between the native seed color and those expressing the set of genes. This automated sorting capability not only enhances the precision of seed selection but also minimizes labor and resource expenditure, ultimately leading to more cost-effective and scalable hybrid seed production. In preferred embodiments the set of genes may confer a characteristic coloration of a progeny seed comprising the set of genes. In certain embodiments, the set of genes may include one or two, or in certain embodiments all three, nucleic acid sequences selected from SEQ ID NO: 4, 7, or 10, or a sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence of SEQ ID NO: 4, 7, 10, in any combination or arrangement. In certain embodiments, the set of genes may include one or two coding sequences selected from SEQ ID NO: 5, 8, or 11, or a sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence of SEQ ID NO: 5, 8 or 11, in any combination or arrangement. In certain embodiments, the set of genes may include one or two nucleic acid sequences encoding an amino acid sequence selected from SEQ ID NO: 6, 9, or 12, or a sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence of SEQ ID NO: 6, 9 or 12, in any combination or arrangement. In the present invention and according to all elements of the present disclosure, the species names Agropyron elongatum, as well as Thinopyrum ponticum are used synonymously to refer to the same taxonomic species.In certain embodiments the set of genes may be from Triticum ponticum, Thinopyrum intermedium, Triticum monococcum, Agroypron elongatum or Agropyron trichophorum, or any combination thereof. In preferable embodiments the set of genes comprises a blue aleurone locus or at least one relevant gene(s) encoding the same. In certain embodiments, the blue aleurone locus may be from Triticum ponticum, Thinopyrum intermedium, Triticum monococcum, Agroypron elongatum or Agropyron trichophorum. In certain embodiments, a color maker can be selected, for example, but not limited thereof, from β-glucuronidase; uidA gene (GUS) (encoding an enzyme for which various chromogenic substrates are known (e.g., U.S. Pat. Nos. 5,268,463 and 5,599,670)); chloramphenicol acetyl transferase; alkaline phosphatase; anthocyanin / flavonoid polynucleotides (e.g., an R-locus polynucleotide (encoding a product that regulates the production of anthocyanin pigments (red color) in plant tissues); genes controlling biosynthesis of flavonoid pigments (e.g., maize C1 and C2, the B gene, the p1 gene, and the bronze locus genes); cyan fluorescent protein (CYP) gene; a the yellow fluorescent protein gene (YFP); red fluorescent protein gene (RFP), yellow-green fluorescent protein (mNeonGreen), a lux gene (encoding luciferase); a green fluorescent protein (GFP), and DsRed2 (Clontech Laboratories, Inc., Mountain View, Calif.); p-lactamase gene encoding an enzyme for which various chromogenic substrates are known (e.g., PADAC, a chromogenic cephalosporin); a xylE gene (encoding a catechol dioxygenase that can convert chromogenic catechols); and a tyrosinase gene (encoding an enzyme capable of oxidizing tyrosine to DOPA and dopaquinone, which in turn condenses to form the easily detectable compound melanin). Also included are any selection markers the presence of which may be detected using, for example, X-ray film, scintillation counting, fluorescent spectrophotometry, low-light video cameras, photon counting detectors (e.g., cameras), and / or multiwell luminometry. In yet a further aspect, the present invention relates to an engineered alien addition chromosome, or an arm or part thereof, or a vector or an expression construct or a synthetic construct comprising or encoding the same, wherein the engineered alien addition chromosome is as defined in the above first aspect. In certain embodiments, vector or an expression construct or a synthetic construct, or any nucleic acid construct encoding or comprising an engineered alien addition chromosome, or an arm or part thereof, may be used, optionally combined with mutagenesis, to introduce an engineered alien addition chromosome, or an arm or part thereof, into at least one cereal plant cell of interest to generate a cereal plant carrying an engineered alien addition chromosome, or an arm or part thereof, of the present invention, or a precursor thereof. In yet a further aspect, there is provided the use of an engineered alien addition chromosome, or an arm or part thereof, or of a sequence encoding or comprising the same, or of a plant, plant cell, or seed comprising the same, for enhancing breeding, particularly by facilitating the selection of seeds based on a color phenotype and / or by increasing the number of male sterile seeds or gametes for expediting hybrid seed production and breeding. A seventh aspect relates to a set of genetic markers for screening for and / or for identifying a cereal plant comprising an engineered alien addition chromosome, or for screening, identifying, or mapping the engineered alien addition chromosome, or the chromosomal unit, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J, and / or at least one of markers L to Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively, alone or in combination with at least a set of primers specific for identifying at least one or a combination of gene(s) as defined in SEQ ID NOs: 1, 4, 7, 10 and / or 13. In the various embodiments relying on a marker or a set of markers as disclosed herein, markers A to K are suitable for screening assays. These markers are suitable to detect the BLA ancestor chromosome (FIG 3A). Specifically, markers D, marker F, marker G and / or marker J are suitable to specifically identify an alien addition chromosome as shown in FIG 3B. Markers F, G and / or D are specifically suitable to identify the presence of a chromosomal unit of the present invention. Markers C, E and / or K are specifically suitable to identify a BLA ancestor chromosome (FIG 3A) and an alien addition chromosome (FIG 3B), wherein the other markers A, B, and H, are suitable to identify the BLA ancestor. All markers are thus suitable for screening purposes, wherein markers F, G, D and / or J are particularly suitable for determining and identifying the presence of an alien addition chromosome of the present invention as also present in NCIMB 44423, alone or preferably in combination with markers L to Y and / or with primers specific for the male fertility restorer and for at least one gene or a set of genes contributing to a color phenotype. Markers L to Y are specifically suitable to identify an alien addition chromosome of the present invention as also present in NCIMB 44423 as well and additionally serve the purpose of screening for BLA ancestors, as the markers can be used to track the origin of the alien addition chromosome. One embodiment relates to the set of genetic markers, wherein, with reference to the genotype deposited as NCIMB 44423, (i) marker A can be detected by a set of primers comprising or consisting of SEQ ID NO: 19 and SEQ ID NO: 20; (ii) marker B can be detected by a set of primers comprising or consisting of SEQ ID NO: 21 and SEQ ID NO: 22; (iii) marker C can be detected by a set of primers comprising or consisting of SEQ ID NO: 23 and SEQ ID NO: 24; (iv) marker D can be detected by a set of primers comprising or consisting of SEQ ID NO: 25 and SEQ ID NO: 26; (v) marker E can be detected by a set of primers comprising or consisting of SEQ ID NO: 27 and SEQ ID NO: 28; (vi) marker F can be detected by a set of primers comprising or consisting of SEQ ID NO: 29 and SEQ ID NO: 30; (vii) marker G can be detected by a set of primers comprising or consisting of SEQ ID NO: 31 and SEQ ID NO: 32; (viii) marker H can be detected by a set of primers comprising or consisting of SEQ ID NO: 33 and SEQ ID NO: 34; (ix) marker J can be detected by a set of primers comprising or consisting of SEQ ID NO: 35 and SEQ ID NO: 36; and (x) marker K can be detected by a set of primers comprising or consisting of SEQ ID NO: 37 and SEQ ID NO: 38, or for an another genotype comprising the chromosomal unit as defined in claim 5, a homologous set of primers having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned primer SEQ ID NOs, respectively. In certain embodiments, the set of genetic markers may be detectable by specific nucleic acid primer pairs, such as those defined by SEQ ID NOs: 19 to 38, designed to amplify specific loci on the engineered alien addition chromosome. Certain embodiments relate to a set of genetic markers that are specific to genomic regions originating from different species, including Thinopyrum ponticum, Triticum boeoticum, and Triticum monococcum, for example, markers L to Y. In certain embodiments, the set of genetic markers suitable for screening and / or identifying and discriminating the original BLA ancestor chromosome and the re-arranged chromosome includes at least one marker linked to the male fertility restorer (Rf) gene, such as marker D, E, or G, and at least one marker linked to the set of genes for the color phenotype (blue-gene) in the original BLA ancestor chromosome, such as marker A, B, C, F, H, or J. Preferably, gene specific primers can be used for screening and / or identifying alone or in combination with chromosome architecture specific markers. Certain embodiments relate to a set of genetic markers comprising a first subset (e.g., markers G, D, J, F) that is present on both an original and a rearranged engineered alien addition chromosome, and a second subset (e.g., markers A, B, C, H) that is present only on the original chromosome and absent from the rearranged (e.g., GC8.2) chromosome. In certain embodiments, the set of genetic markers is configured for use in a polymerase chain reaction (PCR) or a Kompetitive Allele Specific PCR (KASP) assay to detect the presence or absence of specific chromosomal regions. In certain embodiments, a first set of markers comprises marker E, C or K, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein, specifically for screening purposes for the presence of an ancestor BLA chromosome and / or an alien addition chromosome. In certain embodiments, a first set of markers comprises marker D, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a second set of markers comprises marker F, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a third set of markers comprises marker G, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a fourth set of markers comprises marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a fifth set of markers comprises marker D and marker F, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a sixth set of markers comprises marker D and marker G, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a seventh set of markers comprises marker D and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, an eighth set of markers comprises marker F and marker G, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a ninth set of markers comprises marker F and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a tenth set of markers comprises marker G and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, an eleventh set of markers comprises marker D, marker F, and marker G, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a twelfth set of markers comprises marker D, marker F, and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a thirteenth set of markers comprises marker D, marker G, and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a fourteenth set of markers comprises marker F, marker G, and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a fifteenth set of markers comprises marker D, marker F, marker G, and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a sixteenth set of markers comprises at least one of markers D, marker F, marker G, and marker J together with at least one of markers L to Y, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. In certain embodiments, a seventeenth set of markers comprises marker D, marker F, marker G, and marker J, optionally along with at least one set of primers specific for at least one gene or set of genes contributing to a color phenotype as disclosed herein. The term "homologous set of primers" as used herein refers to a pair of nucleic acid primers which, while not necessarily being identical in sequence to a specifically recited primer pair (e.g., the set of primers defined by a specific SEQ ID NO), is functionally equivalent in its ability to amplify the same or a corresponding genetic marker from a target nucleic acid. This definition accounts for minor, naturally occurring allelic variations such as harmless point mutations (e.g., single nucleotide polymorphisms) or small insertions or deletions within the primer binding sites that may exist between different genotypes or plant lines comprising the same essential chromosomal unit as defined herein, and which do not substantively alter the associated phenotype. A homologous set of primers is therefore designed to be sufficiently complementary to these slightly altered binding sites to ensure successful and specific amplification. This definition also encompasses primers that may be slightly shorter or longer than a reference primer, or primers that include sequence modifications, such as non-complementary tails or degenerate bases, provided that such modifications do not prevent the primary function of specific amplification of the intended target locus. The requirement for a high degree of sequence identity (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) ensures that despite these potential variations, the homologous primer retains the necessary specificity to anneal to the correct target and successfully initiate DNA amplification. Ultimately, a homologous set of primers is one that reliably and specifically amplifies the intended genetic marker from any genotype comprising the relevant chromosomal unit, thereby achieving the same diagnostic or screening purpose as the originally recited primer set. An eighth aspect relates to the use of a set of genetic markers for screening for and / or for identifying a cereal plant comprising an engineered alien addition chromosome, or for screening, identifying, or mapping the engineered alien addition chromosome, or the chromosomal unit, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J, and / or at least one of markers L to Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively. In addition to the gene specific primers and markers associated therewith, and in addition to any one of markers A to K, preferably markers D, F, G and / or J (D, F, G and / or J in case a precise identification and determination of the presence of the alien addition chromosome is of interest) the marker panel comprising at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen or all fourteen marker(s) L, M, N, O, P, Q, R, S, T, U, V, W, X and / or Y allows tracing the origin of the alien addition chromosome, since the markers, as described in Example 11, appear rearranged both in the BLA ancestor and in the alien addition chromosome in GC8.2 and variants thereof with a misdivision rate as favorably observed herein. The markers are therefore highly suitable for identifying an alien addition chromosome with the basic structure of GC8.2, and can thus serve as screening tools, either alone or in combination with additional markers and primers as described herein. In certain embodiments, the use of the set of genetic markers is for marker-assisted selection in a breeding program to accelerate the development of stable hybrid cereal plant lines. Certain embodiments relate to the use of the set of genetic markers to screen progeny and confirm the presence and structural integrity of the engineered alien addition chromosome, such as the GC8.2 chromosome. In certain embodiments, the use of the set of genetic markers involves mapping the physical locations of the male fertility restorer gene and the set of genes for the color phenotype on the arms of the engineered alien addition chromosome. Certain embodiments relate to the use of the set of genetic markers to discriminate between a stable, rearranged engineered alien addition chromosome (e.g., GC8.2) and its non- rearranged progenitor by simultaneously screening for the presence of retained markers (e.g., G, D, J, F) and the absence of lost markers (e.g., A, and B). In certain embodiments, the use of the set of genetic markers is for quality control, specifically to identify and select cereal plants having a low misdivision rate of ≤ 0.5%, preferably ≤ 0.2%, by confirming the presence of the rearranged chromosomal unit. Certain embodiments relate to the use of the set of genetic markers in a multiplex assay to simultaneously verify the linkage of the male fertility restorer gene and the color phenotype gene on the chromosomal unit in a high-throughput manner. One embodiment relates to the use of the set of genetic markers for identifying a cereal plant having a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes as determined by a phenotypic color sorting screen as detailed herein. Examples Example 1: Cytological analysis of the original BLA chromosome The structure of the original BLA chromosome was determined with sequential fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) experiments. FISH with two oligonucleotide probes was used to identify individual wheat and BLA chromosomes (FIG 15A). Oligo-pSc119.2-1 and Oligo-pTa535-1 were labelled with 6-carboxyfluorescein (6-FAM) and 6-carboxytetramethylrhodamine (Tamra) generating green and red signals, respectively. Chromosomes were counterstained with 4’,6-diamidino-2-phenylindole (DAPI) (Invitrogen Life Science, Carlsbad, CA, USA) in Vectashield (Vector Laboratories, Burlingame, CA) and pseudo-colored blue. Sequential GISH was performed on the same cell after stripping off the oligo probes in 50% FA / 1x SSC and 50% FA / 0.5x SSC for 10 min each at 42 °C. GISH followed the procedure of Zhang et al., 2001 (Zhang et al., The centromere structure in Robertsonian wheat-rye translocation chromosomes indicates that centric breakage-fusion can occur at different positions within the primary constriction, Chromosoma (2001), 110, 5, 335-344). Total genomic DNA of Pseudoroegneria stipifolia (StSt, 2n = 2x = 14, PI 314058, The National Small Grains Collection, USDA-ARS) was used as probe, which was labelled with biotin-16-dUTP (Roche Diagnostics Australia, Castle Hill, NSW, Australia) using nick translation. Unlabeled total genomic DNA of CS wheat was used as blocker with a probe:blocker ratio of 1:120. Signals were detected with fluorescein–avidin DN (Vector Laboratories). Chromosomes were counterstained with DAPI and pseudo-colored red (FIG 15B). FIG 15C shows the GISH results (hereafter called “ABD-GISH”) using total genomic DNA from Triticum urartu (genome AA) and Aegilops tauschii (genome DD) labeled with fluorescein-12-dUTP and tetramethyl-rhodamine-5-dUTP (Roche, Basel, Switzerland), which fluoresced green and red, respectively. Total genomic DNA of Ae. speltoides (genome SS) was used as a blocker at a probe:blocker ratio of 1:10. GISH enabled distinction of the A-, B-, and D-genome chromosomes and identification of detectable intergenomic translocations if present. T. urartu genomic DNA hybridised to the short arm of the BLA chromosome (FIG 15C) confirming the close homology between T. urartu and T. boeoticum. Surprisingly, instead of the complete long arm, only a bit over half of the distal long arm of the BLA chromosome showed hybridisation signals using the Pseudoroegneria stipifolia (St) genomic DNA as probe (FIG 15B). ABD-GISH showed that the proximal region of the BLA chromosome was from wheat chromosome 4BL. Therefore, the original proposal (Li et al., Selection and identification of wheat alien translocation chromosome 4BS.4AgL. J Xi’an United University (2001) 4:16-21) on the generation of the BLA chromosome through Robertsonian translocation between a whole- arm translocation T4BS.4AgL and chromosome 4Bo of T. boeoticum was incorrect (FIG 17A). Based on our results, the original translocation in the materials in Li et al. (2001) is not a Robertsonian translocation, instead, the translocation breakpoint is on the long arm of chromosome 4B (T4BS.4BL-4AgL). Further Robertsonian translocation occurred between T4BS.4BL-4AgL and chromosome 4Bo of T. boeoticum, generating the BLA chromosome T4BoS.4BL-4AgL (FIG 17B). The derived structure of the BLA chromosome based on cytology analysis was further confirmed by the sequence analysis of the BLA chromosome. The short arm is approximately 260 Mb; proximal half of the long arm belongs to the wheat chromosome 4BL, which is about 180 Mb; and the distal half of the long arm is from Th. ponticum, approximately 181Mb (FIG 18). Example 2: Characterization of the Probus deletion Probus deletion is an X-ray-induced mutant containing a deletion on chromosome 4BS (Fossati & Ingold, A male sterile mutant in Triticum aestivum. Wheat Inform. Serv. (1970) 30:8–10; Driscoll, Cytogenetic analysis of two chromosomal male-sterility mutants in hexaploid wheat. Aust. J. Biol. Sci. (1975) 28:413–416). To characterise this deletion, wheat 90K SNP genotyping was performed on wheat lines with or without Probus deletion. Four wheat lines; AR (homozygous Probus deletion), FAR (without Probus deletion), Maringa D3, and Maringa D183 (the two Maringa lines were 4BS deletion lines created by sodium azide-induced mutagenesis) (Miraghazadeh et al., The use of SNP hybridisation arrays and cytogenetics to characterise deletions of chromosome 4B in hexaploid wheat (Triticum aestivum L.). Theor. Appl. Genet. (2016) 129:2151-2160) were germinated and grown in a glasshouse. Leaves of two-week old seedlings were collected, and DNA extracted using CTAB DNA extraction method (Doyle & Doyle, A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemical Bulletin (1987) 19: 11– 15). Two biological replicates of each sample were genotyped with the Illumina 90K wheat iSelect Infinium SNP chip at the GrainDataGen (Agriculture Victoria) in Australia. Data was analysed in GenomeStudio. SNP markers located in the Probus deletion and at the boundary of the deletion were mapped in the Chinese Spring (CS) wheat reference genome (RefSeq v1.0) to determine the size of the deletion. 90K SNP genotyping identified SNPs inside the deletion region as shown in Table 1, which showed that the deletions in Maringa deletion lines D3 and D183 were larger than the Probus deletion. Probus has an interstitial deletion located in the distal region of 4BS. Table 1 shows the 90K SNP genotyping identified deletions (D) in Probus (AR) and Maringa (D3, D183). Table 1 dlofetflaucn cee semlomn enamoginssIndex on iSelecteg du 90K NP beeA S ad Rs rh chip Type N P C AR D3 D183 67263 Poly scaffold25005 4B . . D 32857 Null scaffold64103 4B . . D 69062 Poly scaffold64103 4B D . D 34257 Poly scaffold150014 4B D . D 80662 Null scaffold150014 4B D . D 33641 Null scaffold150014 4B D . D 73600 Poly scaffold86681 4B D D D 49194 Poly scaffold10200 4B D D D 27329 Poly scaffold10200 4B . D D 2333 Null scaffold10200 4B . D D 58189 Poly scaffold118668 4B . D D 26696 Poly scaffold110677-2 4B . D D The SNP markers were retrieved and mapped to the CS wheat reference genome (RefSeq v1.0) to identify the size of the deletion. As shown in Table 2, the size of the Probus deletion is approximately 5 - 6 Mbp. The three respective SEQ ID NOs define the two allele-specific primers and the common primer. Table 2 Index on iSelect 90K SNP bead Position on chip SNP id SNP name Position 4B (bp) 32857 IWB32857 GENE-2267_230 outside deletion 10,591,726 Tdurum_contig25403_ 69062 IWB69062 648 inside deletion 34257 IWB34257 GENE-4933_1085 inside deletion14,122,723wsnp_Ku_c7180_1240 80662 IWA7268 3155 inside deletion 12,891,978 33641 IWB33641 GENE-3866_301 inside deletion12,230,352Tdurum_contig82942_ 73600 IWB73600 681 inside deletion 15,416,556 Kukri_rep_c106598_11 49194 IWB49194 4 inside deletion 16,056,985 27329 IWB27329 Excalibur_c52594_88 outside deletion 16,059,211 KASP primers for allelic detection of GENE-4933_1085 are defined by SEQ ID NO: 77 (IWB34257-X), SEQ ID NO: 78 (IWB34257-Y), SEQ ID NO: 79 (IWB34257-com). KASP primers for allelic detection of wsnp_Ku_c7180_12403155 are defined by SEQ ID NO: 80 (IWA7268-X), SEQ ID NO: 81 (IWA7268-Y), SEQ ID NO: 82 (IWA7268-com). Example 3: Markers for the BLA hybrid wheat system The original BLA hybrid wheat system comprises three important components, a ‘Probus’ deletion (ms1b) on chromosome arm 4BS causing male sterility, and a monosomic alien chromosome containing a fertility restorer (Rf-Ms1) from Triticum boeoticum on the short arm and a morphological marker, blue aleurone locus from Thinopyrum ponticum on the long arm. Molecular markers detecting these components are important for rapid and reliable selection of materials and constructing female lines. Notably, the terms Rf-Ms1, Rf, and Ms1 are used interchangeably herein to refer to the fertile restorer gene. As the Probus deletion is in the distal region of 4BS, markers located in this region were used to develop the Probus deletion marker. SNP marker XBS000100115 was Blast searched in the NCBI database (https: / / blast.ncbi.nlm.nih.gov / ), and it is part of the EST HX146265 sequence. Three homologous gene sequences of HX146265 were retrieved from the CS (Chinese Spring) reference genome RefSeq v.1. A robust marker, 4BS-HX, was developed for detecting the deletion from analysis of the three homoeologous sequences. The 4BS-HX markers are defined by SEQ ID NO: 60 and 61. PCR was performed using GoTaq DNA polymerase (Promega). Briefly, 50 – 100 ng DNA in a buffer containing 1x GoTaq buffer, 2.0 mM MgCl2,0.2 mM dNTPs, 0.2 µM of each primer, and 0.25 U of GoTaq in a 10 µl reaction. PCR was performed in a T100 thermal cycler (BioRad), with 3 min of 95 °C, then 35 cycles of 20 sec of 94 °C, 20 sec 56 °C, and 30 sec of 72 °C, last extension of 3 min 72 °C. The PCR product was analysed using agarose gel electrophoresis or QIAxcel High Resolution kit (QIAGEN). If the sample was homozygous for the Probus deletion, a single PCR band of 260 bp was amplified, corresponding to the regions on chromosomes 4A and 4D. Although this band was not directly related to the Probus deletion, it served as a positive control for the PCR assay. In cases where the sample was either heterozygous for the Probus deletion or lacked the deletion entirely, two bands were amplified: a 260 bp band and a 230 bp band. The 230 bp band was specifically amplified from chromosome 4BS, where the Probus deletion was located, as illustrated in FIG 12A. Additionally, the Probus deletion was genotyped using a set of KASP markers. These KASP markers were developed based on SNP markers identified in the deletion region through 90K genotyping, which facilitated the determination of Probus deletion status, as detailed in Example 4. Markers for fertility restorer Rf-Ms1 Male sterility gene Ms1 has been cloned in wheat (Tucker et al., Molecular identification of the wheat male fertility gene Ms1 and its prospects for hybrid breeding. Nature Comm (2017), 8:869). An Ms1 homolog in T. boeoticum was cloned from BLA restore line (blue line) by reverse transcription PCR using RNA extracted from developing anthers as a template. This showed 89% sequence identity at the CDS level and 91% identity at the protein level when compared to wheat Ms1 gene, and almost 100% identity with T. monococcum Ms1. This male fertility restorer from T. boeoticum was named Rf-Ms1. Based on its sequence, an Rf-Ms1 specific marker was developed. The respective primer sequences are defined by SEQ ID NO: 62 and 63. The PCR protocol was identical to the previously described method, except that the annealing temperature was set to 66 °C. The PCR product was approximately 80 bp in size if the sample contained the restorer gene. As this is a dominant marker, the absence of amplification indicated that the sample lacked the restorer gene. Following the sequencing of the BLA, the genomic sequence of Rf-Ms1 was compared with the Ms1 sequences from wheat chromosomes 4A, 4B, and 4D. Based on this comparison, a co-dominant marker for Rf-Ms1 was developed, with primer sequences defined by SEQ ID NO: 64 and 65. This marker was designated as Rf-CD. The PCR conditions were similar to those previously described, except with an annealing temperature of 60 °C. The resulting PCR product produced two bands: a 405 bp band corresponding to the alien chromosome and a 456 bp band corresponding to wheat chromosome 4A. FIG 12B illustrates the application of the Rf-CD marker in a population segregating for Rf-Ms1. Markers for color genes Before the BLA chromosome was sequenced, the marker for detecting blue aleurone genelocus was adopted from Li et al. (2017) for the gene ThMYC4E. The respective primers are defined by SEQ ID NO: 66 and 67. The PCR conditions were consistent with those previously described, with an annealing temperature of 56°C. This marker was a dominant marker that produced a 450 bp band if the sample contained the alien chromosome responsible for the blue seed phenotype. Following the sequencing of the BLA chromosome, it was determined that the ThMYC4E gene was located in the distal region of the BLA chromosome, approximately at 616 Mbp. Additionally, another locus associated with the blue seed phenotype was identified, consisting of a three-gene cluster, including MYB, MYC, and F35H. This three-gene cluster was found in the middle of the long arm of the BLA chromosome, around 480 Mbp. This location corroborated findings in an exemplary GC8.2 line, a derivative of a cross between double blue R21 and the Angas ph1b mutant, in which the distal portion of the long arm of the BLA chromosome was deleted, yet the seeds remained blue. A new co-dominant marker for this set of genes was developed by comparing the F35H sequence with the homologous sequence from wheat chromosome 4D. The primer sequences for this marker are defined by SEQ ID NO: 68 and 69. The PCR conditions were as mentioned above, with an annealing temperature of 56°C. This marker yielded a 170 bp band from the BLA chromosome and an 86 bp band from chromosome 4D. The results for the marker F35H-CD are shown in FIG 12C. Markers for the three critical components of the BLA system – the 'Probus' deletion (ms1b), the fertility restorer (Rf-Ms1), and a morphological marker for set of genes, specifically the blue aleurone three-gene cluster – could be analyzed together in a single agarose gel or using the QIAxcel High Resolution kit (QIAGEN) (see FIG 4). KASP primers for allelic detection of the Blue locus are defined by SEQ ID NO: 83 (F35H- BLA-X), SEQ ID NO: 84 (F35H-4D-Y), SEQ ID NO: 85 (F35H common primer). Engineered alien chromosome specific markers For a structural assessment of the GC8.2 engineered alien addition chromosome, eight wheat DNA samples, comprising two biological replicates each of AR5 (AR5_1, AR5_2), AR5B (AR5B_1, AR5B_2; identical genotype to AR5, but with an additional alien BLA chromosome), AR6 (AR6_1, AR6_2; a different genotype from AR5), and AR6B (AR6B_1, AR6B_2; identical genotype to AR6, but with an additional alien BLA chromosome), were genotyped using DArTseq (https: / / www.diversityarrays.com / ) to identify specific sequences (markers) associated with the BLA chromosome. By analyzing sequences present exclusively in samples AR5B_1, AR5B_2, AR6B_1, and AR6B_2, but absent in AR5_1, AR5_2, AR6_1, and AR6_2, ten BLA-specific markers were developed. These markers were subsequently evaluated using AR and AR-B lines, alongside Chinese Spring and several wild species, including Triticum monococcum, T. boeoticum, Pseudoroegneria stipifolia, Th. intermedium, and Th. ponticum. The markers were also tested on translocation lines that possess a modified BLA chromosome. Primer sequences and chromosome locations are provided in Table 3 and FIG 3. Table 3 Primer SEQ ID Marker name NO: Annealing Specific to genome Linkage L-arm, Blue- A 5565329F 19 60 °C Thinopyrum ponticum gene 5565329R 20L-arm, Blue- B 5570804F 21 60 °C Th. ponticum gene 5570804R 22Triticum boeoticum, L-arm, Blue- C 5564956F 23 60 °C Th. ponticum gene 5564956R 24D 5008421F 25 60 °C T. boeoticum S-arm, Rf 5008421R 26T. monococcum, Th. E 3573220F 27 60 °C ponticum S-arm, Rf 3573220R 28T. monococcum, T. L-arm, Blue- F 5565375F 29 60 °C boeoticum gene 5565375R 30G 1861695F 31 60 °C Th. ponticum S-arm, Rf 1861695R 32L-arm, Blue- H 5571044F 33 60 °C Th. ponticum gene 5571044R 34L-arm, Blue- J 5570850F 35 70 °C Th. ponticum gene 5570850R 36 L-arm, Blue- K 5565089F 37 57 °C Th. ponticum gene 5565089R 38 The PCR was conducted using a two-step profile consisting of 35 to 40 cycles of denaturation at 94°C for 10 seconds and annealing at the specified temperature for 30 seconds. The resulting products included a band of approximately 70 bp if the BLA chromosome was present. Marker F was found to co-segregate with the blue-gene locus. Following the sequencing of the original BLA chromosome, these markers were mapped onto the BLA chromosome, with their precise positions illustrated in FIG 3, left. These markers were also utilized to study GC8.2, with their presence or absence in GC8.2 depicted in FIG 3, right. Gametocidal (Gc) gene marker development In the development of GC8.2, the “cuckoo” gene from chromosome 2Ccof Aegilops cylindrica was used to induce chromosome rearrangement and a specific marker for detecting chromosome 2Ccwas needed. Wheat group 2 chromosome COS (Conserved Orthologous Sequence) markers were used to identify polymorphism between wheat and Ae. cylindrica. A total of 19 COS markers (Howard et al., Identification of a major QTL controlling the content of B-type starch granules in Aegilops. J Exp Bot. (2011) Mar; 62(6):2217-28) were used to screen for differences between wheat and Ae. cylindrica. DNA samples of Chinese Spring (CS) and CS 2Ccdisomic addition line (CS+2Cc) were used as templates. PCR products of each marker were analysed using HRM (High Resolution Melting). The product of marker 2U showed a clear difference in the melting curve. The PCR products were sequenced and wheat and Ae. cylindrica sequences were identified. A KASP marker was developed from the sequences. Gel electrophoresis of the KASP products did give sufficient separation (FIG 12D). The KASP primer sequences of 2Cc specific marker 2U are defined by SEQ ID NO: 70 (2U-Gc), 71 (2U-2AS) and 71 (2U- common). Proof of the three-gene cluster conferring blue phenotype in grain It could be demonstrated that selected GC8.2 lines expressed blue phenotype in the grain. It was found this line had lost the distal part of the alien chromosome long arm. While it retained alien markers J and F, it, inter alia, lost markers A, B, C, and H. Markers for Rf, the three-gene cluster, and MYC616 on certain GC8.2 lines were applied, and it was confirmed that these lines had Rf and the three-gene cluster, but had lost MYC616. The three-gene cluster was therefore functional for the blue grain phenotype. The marker sequences of MYC616-CD suitable for screening are defined by SEQ ID NO: 73 and 74. PCR conditions were the same as above but with 58 °C annealing and 90 sec of extension at 72 °C. Example 4: Screening of CG8.2 candidates Normal colored, here white, seeds were sown in SSD trays, grown to anthesis and assessed for visibly fertile anthers.208 plants per sister line were phenotyped. Six GC8.2 sister lines were identified as having no pollen producing anthers. Phenotypic analysis was conducted on these lines in this initial screening. This led to the discovery of multiple sister lines carrying the GC8.2 BLA chromosome. Initially seeds were tested genetically with the below results, the common primers for the Blue gene marker and Triticum boeoticum Ms1 (BoMs1 also named TboMs1 herein) markers are respectively defined by SEQ ID NO: 75 and 76. The individuals from exemplary lines GC8.2_13 and GC8.2_46 were tested using KASP analysis, as shown in Table 4. Table 4 Tested individuals individuals with BoMs1 detected GC8.2_13 1442 GC8.2_46 1456 1 total 2898 F2 screening results Single crosses between GC8.2_13 and the paternal lines (F1) were generated and subjected to genetic screening. BLA 4BS primers were utilized to detect the 4B region within the Probus deletion, while specific primers were employed to determine the relative copy number of a native wheat gene in each sample. The results were presented as a ratio of the 4B primer product to the specific primer product. Ratios of 0, 1, or 2 were observed: a ratio of 0 indicated the absence of the BLA4B sequence (homozygous Probus deletion), a ratio of 1 indicated heterozygous deletion status, and a ratio of 2 indicated homozygous non-deletion. Only F1 individuals exhibiting a ratio of 1 (heterozygous deletion) were selected for selfing. The resulting F2 seeds were genetically tested regardless of the 4B deletion status. Genetic screening was conducted using the Blue gene (with a marker sequence as defined by SEQ ID NO: 75) and BoMs1 (with a marker sequence as defined by SEQ ID NO: 76) KASP markers. Seeds were initially classified visually as either white or blue, but the genetic marker data was primarily relied upon for accurate classification, due to occasionally low expression of the blue color. F3 Screening results The remaining F2 blue seeds were screened to confirm the Probus deletion status on chromosome 4B from multiple recurrent parents using KASP markers. A null amplification result indicated the presence of the Probus deletion. The use of four markers significantly reduced the number of false selections. Specifically, any amplification from any of the four markers that indicated a non-homozygous deletion line was subsequently discarded. Only lines that showed null amplification across all four markers were confirmed as homozygous for the Probus deletion. The KASP primers for Table 5 lists the weeca primers for copy number determination of a wheat gene. Table 5 ID Primer_AlleleX Primer_AlleleY Primer_Common Marker Sequence we07652s01as003 SEQ ID NO: 92 SEQ ID NO: 93 SEQ ID NO: 94 SEQ ID NO: 95 we42657s01as002 SEQ ID NO: 96 SEQ ID NO: 97 SEQ ID NO: 98 SEQ ID NO: 99 we43273s01as002 SEQ ID NO: 100 SEQ ID NO: 101 SEQ ID NO: 102 SEQ ID NO: 103 we74781s01as002 SEQ ID NO: 104 SEQ ID NO: 105 SEQ ID NO: 106 SEQ ID NO: 107 The selected blue plants were cultivated, and seeds were harvested to produce F3 seed. White F3 seeds (homozygous for the Probus deletion) from these plants were then sown in SSD trays, following the protocol used in the initial screening experiment. However, in this experiment, the plants were allowed to grow to full maturity, with approximately one- third of the plants being bagged at anthesis. At full maturity (harvest ripeness), each individual plant was assessed for its respective seed set according to Table 6. Table 6 Total Fertile Total Fertile Maternal Paternal Plants bagged bagged unbagged unbagged Total fertile line line assessed ears ears ears ears ears GC8.2_13 A20_6110 942 264 678 3 3 GC8.2_13 KM19102 900 259 1 641 1 GC8.2_13 KM20003 313 313 0 GC8.2_13 KM20005 721 255 1 466 1 GC8.2_13 KM20030 394 234 160 1 1 GC8.2_13 KM22053 799 265 534 1 1 Total 4069 1277 2 2792 5 7 The blue aleurone three-gene cluster was detectable by respective sets of primers in line GC8.2, as shown in FIG 14. Specific PCR primers (markers) for gene MYB480, MYC480, and F35H480 were developed according to the gene sequences from the original BLA chromosome. These markers were tested in GC8.2. They gave the right size (~400-450 bp) band as expected for these genes in GC8.2. The following primers were used: F35H480-sp-F (SEQ ID NO: 86), F35H480-sp-R (SEQ ID NO: 87), MYC480-sp-F2 (SEQ ID NO: 88), MYC480-sp-R (SEQ ID NO: 89), MYB480-sp-F (SEQ ID NO: 90) and MYB480- sp-R (SEQ ID NO: 91). Example 5: Blue / white seed segregation of line GC8.2 The blue seeds in the BLA system contain 42 wheat chromosomes along with a monosomic addition of the BLA chromosome. During meiosis on the male side, the average frequency of gametes with 21 chromosomes was observed to be 96%, with a range of 81-99% depending on genotype and environmental conditions, as calculated from experimental observations (Morris and Sears, The cytogenetics of wheat and its relatives. Quisenberry and Reitz, Eds., Wheat and Wheat Improvement, Madison (1967), 19-87). In contrast, gametes with 22 chromosomes occurred at an average frequency of 4%, with a range of 1-19%. This discrepancy was attributed to certation, where male gametes with 21 chromosomes were more competitive than those with 22 chromosomes in fertilizing female gametes, likely due to differential growth rates of pollen tubes. On the female side, the additional chromosome was lost in approximately 75% of the female gametes, resulting in 21 chromosomes, with the range varying from 61-86% depending on genotype and environmental factors. Conversely, 25% of the gametes retained the additional chromosome, with a range of 14-39%, leading to 22 chromosomes. Using the above frequencies of gametes, the frequencies of different progeny types were calculated, as presented in Table 6. As observed in our studies, the ratio between white and blue progeny from self-pollinated single blue seeds ranged from 1:1 to 3:1, which corresponded well with the empirical frequencies. Table 7 provides the types and frequencies of progeny resulting from the self-pollination of a monosomic addition line. Table 7 Pollen Eggs 21 chromosomes 22 chromosomes 96% (81-99) 4% (1-19)21 chromosomes 42 chromosomes (white) 43 chromosomes (single blue)75% (61-86) 72% (49-85) 3% (0.6-16) 22 chromosomes43 chromosomes (single blue)44 chromosomes (double blue) 25% (14-39) 24% (11-39) 1% (0.1-7) The original BLA chromosome is a submetacentric chromosome. When present as a univalent at the metaphase I stage of meiosis, this chromosome occasionally misdivides at a frequency of approximately 1-2%, leading to the production of white seeds containing the fertility restorer gene. In contrast, the newly generated BLA chromosome GC8.2 is an acrocentric chromosome, which exhibits a significantly reduced likelihood of misdivision compared to the original BLA chromosome. Example 6: Sequencing and assembly of the original BLA-chromosome Triticum aestivum cv. BLA ancestor seeds carrying two copies of the alien BLA chromosome were grown for two weeks, after which the seedlings were subjected to a dark treatment for three days. Leaf tissue from a single plant was then harvested, snap-frozen in liquid nitrogen, and stored at -80°C. Nuclei were isolated from 10 g of the dark-treated, snap-frozen leaf using the method described by Zhang et al. Preparation of megabase-size DNA from plant nuclei, the plant journal (1995), 7, 1, 175-184. High-molecular-weight (HMW) DNA was extracted from the isolated nuclei using a Nanobind Plant Nuclei kit (Pacific Biosciences, Menlo Park, USA) as per the manufacturer's instructions. DNA was repaired using NEBNext FFPE DNA Repair Mix (New England Biolabs, Ipswitch, USA) and then end-prepped using NEBNext® Ultra™ II End Repair / dA-Tailing Module (New England Biolabs, Ipswitch, USA). Prior to ONT adapter ligation, small fragments were removed using Short Read Eliminator XL reagent (Pacific Biosciences, Menlo Park, USA). Size-selected DNA was then adapter ligated using the SQK-LSK114 library prep kit (Oxford Nanopore Technologies, Oxford, UK), bead cleaned, and loaded onto 14 FLO-PRO114M flowcells (R10.4.1 pore) in a PromethION 24 device, as per the manufacturer’s instructions (Oxford Nanopore Technologies, Oxford, UK). After 16-20 hours of sequencing, the nuclease-flush procedure was done as per the manufacturer’s instructions and repeated again after another 16-20 hours of sequencing (Oxford Nanopore Technologies, Oxford, UK). Raw data of the 14 ONT flow cells were basecalled using Guppy 6.4.2 using the SUP model (r1041_prom_sup_g642). The ONT assembly was generated by the 70 % longest reads only using the assembler Shasta 0.11.1 (Lorig-Roach et al., Phased nanopore assembly with Shasta and modular graph phasing with GFAse. Genome Res (2024), 25, 34(3):454- 468). The following settings were used: minReadLength=10000, config Nanopore- May2022, --Kmers.probability 0.07 on a machine with 3TB RAM. The Dovetail Omni-C Kit, a sequence-independent, endonuclease-based, proximity- ligation protocol (Cantata Bio LLC, CA, USA), was used to prepare 12 libraries from 300 mg of the snap-frozen leaf, according to the manufacturer’s protocol (Dovetail_Omni-C- Protocol_Non-mammal_v1.2B). Sequencing was performed as 2^×^150^bp paired-end reads on an S1 NovaSeq6000 run (Hartwig Medical Foundation, The Netherlands). For the pseudomolecule construction, the Omni-C reads were incorporated using yahs version 1.2 (Zhou et al. YaHS: yet another Hi-C scaffolding tool. Bioinformatics (2023), 39(1), btac808) and Juicer_tools (v.1.9.9) (Durand et al., Juicer provides a one-click system for analyzing loop-resolution Hi-C experiments, Cell Systems (2016), 3(1)) following the manufacturer’s instructions. Juice Box (v. 3.0) (Robinson et al., Juicebox.js provides a cloud-based visualization system for Hi-C data, Cell Systems (2018) 6(2)) was employed for manual correction of scaffolds. In brief, a bam file containing valid read pairs was generated using SAMtoos (v1.15.1) (Danecek et al., Twelve years of SAMtools and BCFtools, GigaScience (2021), 10, 2, February 2021, giab008) and pairtools (v0.3.0) (Abdennur et al., Pairtools: from sequencing data to chromosome contacts, bioRxiv [Preprint] (2023)) as described with the following modification: the minimum mapping quality was reduced to 10 (--min-mapq 10). Subsequently yahs was utilized to construct scaffolds using default parameters (Zhou et al. 2023). Then Juicer_tools (Durand et al 2016) and Juice Box (Robinson et al.2018) were used for manual correction of miss-placed contigs and to generate the final scaffolds. For Illumina sequencing DNA was extracted from young leaves by a silica-membrane technology according to NucleoSpin® 96 Plant II (Macherey-Nagel) following the manufacturer’s instructions. Whole Genome Sequencing libraries were prepared by the Hartwig Medical Foundation and sequenced on a NovaSeq6000 to generate 1400 Gbp raw data (Hartwig Medical Foundation, The Netherlands). The ONT HiC scaffolds were polished with Illumina short reads using the polishing tool Hypo (Darian et al 2024). The positive effects of polishing were assessed with the tools Quast (Gurevich et al., QUAST: quality assessment tool for genome assemblies. Bioinformatics (2013). 2013 Apr 15;29(8):1072-5) and Merqury (Rhie et al., Merqury: reference-free quality, completeness, and phasing assessment for genome assemblies. Genome Biol. (2020) Sep 14;21(1):245) and assembly quality (QV value) was noted to improve after polishing. Example 7: Development of oligo probes A French winter wheat cultivar, Triticum aestivum BLA ancestor was sequenced using the Nanopore long-read and HiC sequencing technologies. High quality genome assembly was used as a reference genome. The coordinates of four genes / loci, Ms1, three-gene cluster, MYC_616, and MYB_618, were determined by searching the gene sequences against the reference genome. When designing oligo probes, the coordinates for each locus were expanded to approximately 100 Kb (except for the three-gene cluster, which is 200 Kb) of surrounding regions in order to reach sufficient probe density to generate hybridization signals. Probes were designed by Dr Brian Brunelle, Arbor Biosciences (Ann Arbor, MI, USA) using their proprietary software. Probe candidate sequences were compared with the rest of the genome sequence to ensure that they are mostly single-copy sequences. “Stringent”, instead of “most stringent” (zero matches elsewhere in the genome), specificity cut-off was used in order to have sufficient amount of probes to generate signals. Using a "stringent" cut-off had the potential to produce a few weak hits elsewhere in the genome. However, these were unlikely to be detected. The complete results on the probe count and density for the four loci is shown in Table 8. The final probe represents 1,885 oligos of about 45 nucleotides each, which is approximately 84,825 bp in total. myTags Custom Indexed Flex Synthesis (Arbor Biosciences) was used. Probes were either labeled with Alexa 488 (green fluorescence) or ATTO 550 (red fluorescence) according to the manufacturer’s protocol (Labeling Protocol for myTags Immortal Libraries, v2.2, Arbor Biosciences). Example 8: Rearrangement of the original BLA chromosome As described in the “Background of the invention”, the alien chromosome occasionally undergoes misdivision during meiosis, occurring at a frequency of approximately 1-2%, resulting in the production of white seeds that carry the fertility restorer gene, as depicted in FIG 2A. The consequence of this misdivision is that 1-2% of the white-seeded female materials in an F1 seed production system will be male-fertile and, therefore, capable of producing seed. Furthermore, these fertile spikes can pollinate adjacent sterile spikes, leading to a situation where up to 10% of the resulting F1 seed is effectively non-hybrid. In order to address the issue of misdivision, a gametocidal gene (Gc), often referred to as the “cuckoo” gene, was used to induce chromosome breakage and rearrangement so that the genes encoding fertility restorer and blue aleurone locus would stay together (in an ideal situation, no separation). Gc genes, introduced into common wheat from Aegilops species, are selfish genetic elements that ensure their preferential transmission by inducing chromosome breaks in gametophytes lacking these genes (Finch et al., “Cuckoo” Aegilops addition chromosome in wheat ensures its transmission by causing chromosome breaks in meiospores lacking it. Chromosoma (1984) 90:84-88; Nasuda et al., Gametocidal genes induce chromosome breakage in the interphase prior to the first mitotic cell division of the male gametophyte in wheat. Genetics (1998) 149:1115-1124). The actions of some Gc genes are very strong and result in extensive chromosomal breakage. Importantly, only gametes with the Gc gene are functional. Plants that carry one copy of the Gc gene (hemizygous) are semi-sterile and have 100% transmission of the Gc chromosome to the offspring. Here a weaker Gc gene, i.e. Gc4 located on Ae. cylindrica chromosome 2Cc(Endo, Induction of chromosomal structural changes by a chromosome of Aegilops cylindrica L. in common wheat. Journal of Heredity (1988) 79:366-370) was used, which only induces moderate breakage (major re-arrangements produce too much instability) and the Gc chromosome is not selectively retained. In the offspring the recovery of chromosomal rearrangements is possible. Gc genes have the capability to induce breakage and recombination events within and among chromosomes. Such breakage and subsequent fusion events in the BLA chromosome could bring the set of genes and the male fertility restorer gene into close proximity. This rearrangement would address the issues associated with chromosome misdivision and enhance the stability and functionality of the original 43-chromosome system. Fourteen 43-chromosome BLA lines (designated 21”+BLA’ where BLA’ is the alien addition chromosome) were crossed to a disomic addition line (21”+2CC”) carrying the gametocial gene Gc4 on chromosome 2CC. The F1 progeny comprises 75% white (21”+2CC’) and 25% blue 44 chromosome types (21”+BLA’+2CC’). The blue seeded materials are heterozygous for the 4B deletion and are designated Msms. These lines were crossed to a 43- chromosome BLA line (21”+BLA’) that has the 4B deletion and is designated as msms. From this cross only progeny of the constitution 21”+BLA’ (msms) were retained. Those lines of the constitution Msms were removed using the marker for the Ms1 deletion. Blue seeded progeny without the gametocidal gene had undergone chromosome re- arrangements. These blue seeded materials were self-fertilised to produce blue and white seeded progeny; the white seed were screened for fertility. The blue seeded parental lines of those white seeded progeny that did not show any fertile plant were screened cytologically and markers used to confirm translocation. Fifty-four lines from six families were identified having no white fertile progeny after screening up to 208 white seed for each line. The equivalent blue seed were subject to cytology analysis and marker genotyping for Rf gene. It was found that several lines, including lines #13, 46, and 103 in family GC8.2 had a highly desirable chromosome composition and at the same time excellent overall agronomic performance. GC8.2 was derived from line R33, having 43 chromosomes (42 wheat chromosomes + a newly rearranged acrocentric BLA chromosome). Comparative oligo hybridization to the original Bla-chromosome and GC8.2 1) Original Bla-chromosome Oligo pools for Ms1 (arrowhead 1) and MYC_616 (arrowhead 2) were labeled with ATTO 550 (red fluorescence) and those for three-gene cluster (arrowhead 3) and MYB_618 (arrowhead 4) were labeled with Alexa 488 (green fluorescence, pseudo-colored red). Chromosomes were counterstained with DAPI and pseudo-colored blue. FIG 16 shows the hybridization patterns of four oligo pools on an original BLA line (A, B: Ms1 and MYC_616, C, D: three-gene cluster and MYB_618). Oligos for Ms1 locus hybridised to the distal end of the short arm of BLA chromosome (FIG 16A, B); oligos for MYC_616 locus hybridised to the distal end of the long arm of BLA chromosome. In addition, they also hybridised to the distal 45% of the long arm of wheat chromosome 4B (FIG 16A, B); oligos targeting the three-gene cluster hybridized to the middle of the long arm of the BLA chromosome (FIG 16C, D). Similarly, oligos for MYB_618 exhibited the same hybridization pattern as oligos for MYC_616, hybridizing not only to the distal end of the long arm of the BLA chromosome but also to the distal 45% of the long arm of wheat chromosome 4B (FIG 16C, D). The hybridization sites of all four oligo pools on the BLA chromosome agreed perfectly with their locations deduced from sequence information, i.e. Ms1 on the very distal end of the BLA chromosome (distal 1.2% of the short arm, 3Mb position vs. short arm length of 260Mb); three-gene cluster is nearly in the middle of the long arm of BLA chromosome (position: 480Mb, 180Mb in size vs. long arm length of ~360Mb); both MYC_616 and MYB_618 are at the very distal end of the BLA chromosome (the total length of BLA chromosome is 621Mb). In addition to the BLA chromosome, both hybridized to the distal 45% of the long arm of wheat chromosome 4B due to the sequence similarity in this region. 2) GC8.2 line Cytological analysis was conducted on at least four plants from exemplary lines within the GC8.2 family (FIG 8 to FIG 10) to determine their chromosomal structures. The rearranged BLA chromosome was identified as an acrocentric chromosome, and its structure was consistent across all three lines. As shown in FIG 8 to 10, significant rearrangements were observed, attributed to the breakage and fusion activity of the Gc gene. To elucidate the detailed structure of the GC8.2 chromosome, particularly the positions of the four loci mentioned above, fluorescence in situ hybridization (FISH) was performed using oligo pools specific to these loci (FIG 6 and 7). The oligo pool for MYB_618 did not produce any detectable signal (data not shown), suggesting that the MYB_618 locus is absent in GC8.2. In contrast, the oligo pools for Ms1 and MYC_616 hybridized to the proximal 20% of the long arm of GC8.2, as shown in FIG 11. The oligo pool targeting the three-gene cluster locus hybridized to the short arm of the rearranged BLA chromosome, in close proximity to the centromere (FIG 6). The right panel of FIG 6 illustrates the centromere positions using the centromeric repeat 6-J9 as a probe (Zhang et al., 2004, Chromosoma 112:288-299). The three-gene cluster locus was confirmed to be on the short arm, relative to the centromere position. Notably, the signal intensity of the centromeric repeat in GC8.2 was significantly lower compared to that of the original BLA chromosome, whose signal intensity was comparable to that of wheat chromosome centromeres (right panel, FIG 7). These findings indicate that extensive rearrangements occurred in the original BLA chromosome during the formation of GC8.2, resulting in the current structure of the rearranged chromosome, with the three-gene cluster on the short arm, and the Ms1 and MYC_616 loci on the long arm, positioned very close to each other, if not at the same location. The potential substantial loss of centromeric repeat sequences suggests that some breakages may have occurred within the centromeric region. Based on the FISH results using oligo pools and centromeric repeats as probes, FIG 3 illustrates the structural comparison between the original BLA chromosome and the rearranged BLA chromosome in GC8.2, including the relevant marker information. Example 9: Validation of GC8.2 1) Initial screening of GC8.2 Material: Plants originating from white seed from six different sister plants from the original GC8.2 plant. Grown in standard SSD trays (104 seed / tray) under standard greenhouse conditions. Table 9 lists the genotypes visually assed for pollen shedding anthers. Table 9 Genotype Plants assessed No. of pollen shedding ears GC8.2_13 208 0 GC8.2_46 208 0 GC8.2_103 208 0 GC8.2_33 208 0 GC8.2_89 208 0 GC8.2_91 208 0 Total 1248 0 2) Assessment of GC8.2 Novel cereal plants have been developed. One representative wheat line which shows a reduced misdivision rate compared to the original BLA line as disclosed herein is referred to herein as GC8.2, and was deposited under the Budapest Treaty. Consequently, seeds of this line ([Triticum aestivum], internal designator GC8.2 / KWS0484) have been deposited with the National Collection of Industrial, Food and Marine Bacteria (hereinafter, “NCIMB”) Ltd., Wellheads Place, Aberdeen, Dyce, AB21 7GB, Scotland, Great Britain on 02 / 09 / 2024 by the present applicant and have received accession number NCIMB 44423 (Form BP / 4). As evident from Form BP / 9 as provided by the NCIMB, the material was confirmed to be viable (test of 02 / 09 / 2024) NCIMB is a recognized International Depository Authority under the Budapest Treaty. This deposit of GC8.2 seeds was made under the Budapest Treaty and will be maintained in the NCIMB depository for at least the enforceable life of the patent and will be replaced if the deposit becomes nonviable during that period. Additionally, Applicant has satisfied all the requirements of 37 C.F.R. Sections 1.801-1.809, including providing an indication of the viability of the sample. Material: F1 plants derived from single cross between GC8.2_13 and KWS parental lines were self-fertilized to generate F2 seed. Blue seed were planted and selected with KASP markers for homozygous Probus deletion. White F3 seed were planted in standard SSD trays (104 seed / tray) under standard greenhouse conditions. Of the total 4069 plants, 1277 ears were placed in a cellophane bag to prevent any risk of cross pollination from potential fertile plants. Assessment: Plants were individually assessed visually to identify fully fertile ears, and a total of 5 fully fertile ears were identified, 1 from bagged ears and4 from un-bagged. Seed from there were genotyped. It was confirmed that the misdivision rate is as low as 0.13%. Table 10 shows the phenotype assessment of respective maternal lines. Table 10 Maternal Paternal Plants Total Fertile Total Fertile Total line line assessed bagged bagged unbagged unbagged fertile ears ears ears ears ears GC8.2_13 A20_6110 942 264 678 3 3 GC8.2_13 KM19102 900 259 641 GC8.2_13 KM20003 313 313 0 GC8.2_13 KM20005 721 255 1 466 1 GC8.2_13 KM20030 394 234 160 GC8.2_13 KM22053 799 265 534 1 1 Total 4069 1277 1 2792 4 53) Phenotyping and genotyping of BC1F1 GC8.2 was crossed to selected Australian wheat varieties. Blue seeds from these crosses were further back crossed to the same cultivar used in the first cross to produce BC1F1. Blue seeds of BC1F1 were selected and grown in the 100-cell tray in the glasshouse. Two- week-old leaf of each plant was collected for DNA extraction and genotyping. A total of 243 plants were genotyped using the Probus marker and the Rf specific marker. 106 plants were selected as they are Probus heterozygous and Rf positive, which were transferred to big pots and grown to produce BC1F2 seeds. During genotyping, it was found that one plant in the total 243 plants was Rf negative. It indicated that the short arm and the long arm were separated due to misdivision. This plant was not selected for further growing. 4) Phenotyping and genotyping of BC1F2 A total of 6,156 seeds, including white and blue were genotyped using the Probus marker, the Rf marker, and the ThMYC4E (=MYC616) specific marker. Initially, the BC1F2 generation was phenotyped to differentiate between blue and white seeds, followed by genotyping. Upon genotyping the first 10 plates (in a 96-well format), it was found that at least 5% of the plants grown from white seeds possessed both the Rf gene and the ThMYC4E gene. This observation indicated that the blue gene may not have expressed effectively, possibly due to suboptimal growth conditions. As a result, classification of the plants was performed based on genotype rather than seed color. After genotyping 6,156 BC1F2 plants, a total of 1,531 plants were identified as homozygous for the Probus deletion. Among these, 895 plants were found to lack both the Rf and ThMYC4E genes (white sterile), while 636 plants were found to carry both Rf and ThMYC4E (blue fertile). No segregation was observed between the Rf and ThMYC4E genes. Upon analysis of the GC8.2 BLA chromosome structure alongside the original BLA sequence, it was determined that the Rf and ThMYC4E genes are located in close proximity on the middle of the long arm of the chromosome, ensuring they are inherited together. In contrast, the three-gene cluster in GC8.2 was found to be situated on the short arm, raising the possibility of separation from the Rf / ThMYC4E genes due to chromosomal misdivision. The blue phenotype observed in one plant from the BC1F1 generation, which lacked the Rf gene, was most likely a result of such a misdivision. Following the discovery that the three-gene cluster and the Rf + MYC616 genes are located on different arms of the engineered alien chromosome in GC8.2, 555 of the selected blue fertile plants were re-genotyped using the three-gene cluster marker (F35H-CD) to identify any instances of misdivision. This analysis identified two plants (T35-L4 and T36-I8) that had lost the three-gene cluster (as shown in FIG 5). These plants were subsequently genotyped using the Rf-CD marker, the Probus marker, and the three-gene cluster marker, along with other BLA materials for comparison (as shown in FIG 4). In summary, among the plants generated from 897 white seeds, 895 were phenotypically sterile and lacked the Rf+MYC616 or three-gene cluster, while 2 plants were phenotypically fertile, possessing white seeds and carrying the RF+MYC616 markers. This results in a misdivision rate of 0.22%. 5) Assessment of phenotype of ThMYC4E (MYC616) lacking the three-gene cluster It was confirmed that the three-gene cluster confers the blue seed phenotype as plant T36- I8 comprised seeds that were shriveled and all white. T35-L4 was healthy and harvested seeds were white as well, an influence on MYC616 alone on blue seed coloration could be excluded. 6) Summary Combined data show nine (7+2) misdivided white seeded plants out of 4966 plants (4069+897), which results in a misdivision rate of 0.18%. Example 10: Further screening and phenotypic evaluation BC1F3 seeds Selfing of heterozygous BC1F1 (probus deletion heterozygous) was performed. Then, homozygous (probus deleted) BC1F2 plants were transplanted into the field for seed increase resulting in BC1F3 seed. White seed BC1F3 planted in SSD trays and ears were assessed at maturity for seed set. The results are shown and documented in Table 11 below. Table 11 Recurrent line Total plants White fertile KWS1 208 0 KWS2 416 0 KWS3 312 0 KWS4 104 0 KWS5 104 1 KWS6 208 2 KWS7 208 2 KWS8 208 4 KWS9 208 0 KWS10 208 0 KWS11 312 2 KWS12 208 3 SUM 2704 14PERCENTAGE % 0.52On average, a misdivision rate of 0.52 % was observed by screening for the color phenotype, which is significantly below 1% and values as obtainable for earlier lines with different arrangements of the alien addition chromosome. Such a misdivision rate is highly favourable for stable breeding and subsequent screening to be performed in a reliable and convenient manner. Example 11: Further validation and fine mapping of GC8.2 1) Fine screening of GC8.2 and mapping of a BLA ancestor chromosome and the alien addition chromosome - sequencing Additional marker analysis in 6,000 white seeds was performed. To fully understand the alien addition chromosome architecture, the chromosome of NCIMB 44423 was sequenced. Using similar methods as in example 6, the GC8.2 chromosome was assembled as one scaffold ~ 430 Mb and ~10Mb unassembled contigs. Notably, the marker screen aimed at defining unique markers present in the BLA ancestor chromosome (cf. Example 6 and 7 supra) being representative for the three portions originating from Triticum boeoticum, Triticum aestivum 4B and Thinopyrum ponticum (cf. Example 7 and exemplary FIG.18) to specifically “track” the presence and / or translocation of these chromosome parts of different origin as screening tool. Further, unique markers aimed at fine mapping the alien addition chromosome’s architecture in GC8.2 were designed. 2) Results As shown in Tables 12 (BLA ancestor chromosome) and 13 (alien addition chromosome of GC 8.2 as deposited), 14 new markers, namely Y_Marker, U_Marker, O_Marker, P_Marker, R_Marker, Q_Marker, W_Marker, X_Marker, M_Marker, L_Marker, V_Marker, J_Marker, T_Marker, N_Marker, and S_Marker were identified in addition to F_Marker, G_Marker, D_Marker and J_Marker, wherein the new set of markers allows to map and track both chromosomes, alone and in combination with any one of the marker comprising at least one of marker F, G, D and / or J. The position of all markers along with the centromeric region position as well as the position of relevant gene elements is shown in the below Tables 12 and 13. Approximate start and end positions are indicated as Megabases (Mb). The centromeric region position allows to identify the short and the long arm of the chromosome as sequenced and mapped. Table 12 Element Start position End position Strand G_Marker 2.325.851,00 2.325.908,00 + D_Marker 2.722.483,00 2.722.544,00 + Rf-Ms1 3.184.906,00 3.183.158,00 - L_Marker 12.068.723,00 12.068.723,00 + Y_Marker 79.197.940,00 79.197.940,00 + M_Marker 145.635.102,00 145.635.102,00 + Centromeric region 263.702.587,00 265.250.105,00 NA J_Marker 409.268.412,00 409.268.356,00 - N_Marker 438.993.161,00 438.993.161,00 + MYB480 480.010.251,00 480.009.430,00 - MYC480 480.078.781,00 480.083.239,00 + F35H480 480.191.667,00 480.193.475,00 + O_Marker 483.542.344,00 483.542.344,00 + P_Marker 485.740.695,00 485.740.695,00 + Q_Marker 486.920.980,00 486.920.980,00 + F_Marker 532.502.316,00 532.502.380,00 + R_Marker 538.100.278,00 538.100.278,00 + S_Marker 544.237.150,00 544.237.150,00 + B_Marker 544.675.492,00 544.675.545,00 + T_Marker 547.693.698,00 547.693.698,00 + H_Marker 570.329.030,00 570.329.089,00 + U_Marker 597.986.163,00 597.986.163,00 + V_Marker 610.458.347,00 610.458.347,00 + W_Marker 610.764.799,00 610.764.799,00 + X_Marker 614.517.911,00 614.517.911,00 + MYC616 616.704.114,00 616.691.386,00 - MYB618 618.080.936,00 618.079.898,00 - A_Marker 620.027.474,00 620.027.540,00 + Table 13 Element Start position End position Strand Y_Marker 1.653.161,00 1.653.161,00 + F35H480 45.143.711,00 45.141.903,00 - MYC480 45.256.601,00 45.252.143,00 - MYB480 45.325.127,00 45.325.948,00 + Centromeric region 67.065.977,00 70.947.150,00 NA U_Marker 115.044.881,00 115.044.881,00 + O_Marker 120.999.085,00 120.999.085,00 - F_Marker 122.721.922,00 122.721.986,00 + P_Marker 125.624.952,00 125.624.952,00 + R_Marker 139.544.645,00 139.544.645,00 + Q_Marker 144.082.047,00 144.082.047,00 - W_Marker 145.300.700,00 145.300.700,00 + G_Marker 154.368.484,00 154.368.541,00 + D_Marker 154.765.077,00 154.765.138,00 + Rf-Ms1 155.227.424,00 155.225.676,00 - MYC616 156.825.056,00 156.837.784,00 + X_Marker 159.022.245,00 159.022.245,00 - M_Marker 162.717.737,00 162.717.737,00 + L_Marker 179.360.467,00 179.360.467,00 + V_Marker 192.944.946,00 192.944.946,00 - J_Marker 214.317.541,00 214.317.597,00 + T_Marker 298.304.748,00 298.304.748,00 + N_Marker 315.541.615,00 315.541.615,00 + S_Marker 426.602.066,00 426.602.066,00 + With the above fine mapping and the marker and gene position information available, it is easy to screen a given germplasm for the presence or absence of an alien addition chromosome having extremely low misdivision rate of ≤ 1% or even below. The new set of markers L to Y thus represents a set of markers to screen for the original and the rearranged alien addition chromosome architecture and thus to identify the presence or absence of the GC8.2-type alien addition chromosome. Specific sequences for markers and to create primers for screening the relevant genes are also provided in the attached sequence listing. The skilled person is well aware of the fact that markers for homologous, orthologous or paralogous sequences can be easily defined based on the sequence information provided to cover slight variations.

Claims

Claims 1. A cereal plant comprising an engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes, wherein the set of genes comprises at least one gene cluster and / or at least one individual gene contributing to a color phenotype in the cereal plant, preferably seed coloring, (i) wherein the engineered alien addition chromosome has a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes; and / or (ii) wherein the male fertility restorer gene and the set of genes are independently located within 40%, preferably within 30%, more preferably within 20% relative distance to the centromere of the engineered alien addition chromosome; and / or (iii) wherein the male fertility restorer gene is located on the same chromosomal arm with at least one gene cluster and / or at least one individual gene contributing to the color phenotype; and / or wherein at least one gene cluster and / or at least one individual gene contributing to the color phenotype is located on a different chromosome arm than the male fertility restorer gene.

2. The cereal plant according to claim 1, wherein the at least one gene cluster contributing to the color phenotype is located on the short arm of the engineered alien addition chromosome and the male fertility restorer gene is located on the long arm of the engineered alien addition chromosome.

3. The cereal plant according to claims 1 or 2, wherein the at least one individual gene contributing to the color phenotype and the male fertility restorer gene are one the same arm of the engineered alien addition chromosome.

4. The cereal plant according to any of the preceding claims, wherein the set of genes comprises or consists of F35H480, MYC480, MYB480 and / or MYC616, wherein F35H480, MYC480, MYB480 form a gene cluster, being defined by the sequences as set forth in claim 17 (vii) to (xii).

5. A chromosomal unit comprising the set of genes defined in any of the preceding claims and the male fertility restorer gene as defined in any of claims 1 to 3, wherein said genes are located within a genomic interval, the interval spanning from the gene cluster asdefined in claim 4 to MYC616 as defined in claim 4 and comprising in-between the gene cluster and MYC616 the male fertility restorer gene as defined in any of claims 1 to 3.

6. The cereal plant according to claims 1 to 4, wherein the cereal plant comprises, preferably homozygously, a male fertility gene mutation, which is a gene deletion, a gene knockdown, or a gene knockout, preferably wherein the male fertility gene is Ms1 or a nucleic acid as defined comprising a nucleic acid sequence independently selected from the group consisting of: (i) a nucleic acid as set forth in SEQ ID NO: 47, 50, 54 or 57; (ii) a nucleic acid sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 47, 50, 54 or 57; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 48, 51, 55, or 58; (iv) a nucleic acid sequence having a coding sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 48, 51, 55 or 58; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 49, 52, 56 or 59.

7. The cereal plant according to any of the preceding claims, wherein the cereal plant comprises one additional chromosome to its euploid number of chromosomes, wherein the male fertility restorer gene and the set of genes as defined in any of the preceding claims are on the additional chromosome.

8. The cereal plant according to any one of the preceding claims, wherein the cereal plant is a diploid wheat, tetraploid wheat, hexaploid wheat, or triticale.

9. A cell, a seed, or a progeny or part thereof of the cereal plant according to any one of the preceding claims, wherein the cell, the seed, or the progeny or part thereof comprises the male fertility restorer gene as defined in any of claims 1 to 3, or 5, and the set of genesas defined in any of claims 1 to 5, or 7, or wherein the cell, the seed, or the progeny or part thereof comprises the alien addition chromosome as defined in claims 1 to 7 and / or chromosomal unit according to claim 5.

10. A method for selecting and / or sorting of at least one male-sterile seed of a cereal plant comprising the steps of: (i) separating, preferably automatically separating, from the progeny according to claim 9 a colored seed from an normal seed, wherein the at least one normal seed is male-sterile female; and (ii) obtaining a cereal plant, including a hybrid cereal plant, a part of a cereal plant, a progeny thereof, a cell and / or a seed thereof.

11. A method of generating a color-coded male sterile system for phenotypic and / or genetic selection of a cereal plant comprising: a) selecting a cereal plant line comprising a male fertility gene mutation, preferably wherein the male fertility gene mutation is homozygous, wherein the cereal plant line comprises at least one engineered alien addition chromosome carrying a male fertility restorer gene as defined in any of claims 1 to 3, or 5, and a set of genes as defined in any of claims 1 to 5, or 7, or wherein the cereal line comprises a chromosome comprising a chromosomal unit as defined in claim 5; and b) optionally: rearranging the at least one engineered alien addition chromosome, wherein the rearranging step comprises using the presence of a gametocidal gene which induces breakage and rearrangement of the at least one engineered alien addition chromosome, to the cereal plant line of step a), wherein the gametocidal gene is located on a monosomic or a disomic gametocidal addition chromosome; and / or c) optionally: applying mutagenesis to at least one cell, seed, plant or part of a plant of the cereal plant line of step a), wherein mutagenesis is selected from genome editing, chemical and radiation induced mutagenesis, or a combination thereof; and d) obtaining a cereal plant comprising a rearranged engineered alien addition chromosome as defined in any one of claims 1 to 5.

12. The method according to claim 10 or 11, wherein the engineered alien addition chromosome is monosomic.

13. The method according to claim 11 or 12, wherein the gametocidal gene is introduced as a monosomic addition chromosome, and / or the gametocidal gene is the gametocidal factor located on chromosome 2Ccof Aegilops cylindrica.

14. The method according to any of claim 10 to 13, wherein the method additionally comprises (x) screening for and / or identifying the presence of the engineered alien addition chromosome carrying a male fertility restorer gene and a set of genes as defined in claims 1 to 4, and (y) selecting and / or sorting at least one seed according to claim 6 based on a color phenotype in the cereal plant contributed by the activity of the set of genes as defined in claims 1 or 2.

15. The cereal plant according to claims 1 to 8, wherein the engineered alien addition chromosome is additionally modified by mutagenesis and / or genetic engineering, wherein mutagenesis includes chemical mutagenesis, radiation mutagenesis, and genome editing, wherein genome editing includes editing by site-directed nucleases, including zinc-finger nuclease (ZFNs) systems, transcription activator-like effector nuclease (TALENs) systems, meganuclease systems and CRISPR / Cas systems.

16. An engineered alien addition chromosome, including an isolated engineered alien addition chromosome, as defined in any of claims 1 to 4, 9, 12 or 15.

17. The cereal plant according to claims 1 to 8, or the chromosomal unit according to claim 5, or the engineered alien addition chromosome according to claim 16, wherein the male fertility restorer gene comprises a nucleic acid sequence selected from the group consisting of: (i) a nucleic acid sequence as set forth in SEQ ID NO: 1; (ii) a nucleic acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 1; (iii) a nucleic acid sequence having a coding sequence as set forth in SEQ ID NO: 2; (iv) a nucleic acid sequence having a coding sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 2; (v) a nucleic acid sequence encoding an amino acid sequence as set forth in SEQ ID NO: 3; and (vi) a nucleic acid sequence encoding an amino acid sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 3; and / or wherein the set of genes comprises a nucleic acid sequence independently selected from the group consisting of: (vii) a nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (viii) a nucleic acid sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence as set forth in SEQ ID NO: 4, 7, 10 and / or 13; (ix) a nucleic acid sequence having a coding sequence of SEQ ID NO: 5, 8, 11 and / or 14; (x) a nucleic acid sequence having a coding sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the nucleic acid sequence of SEQ ID NO: 5, 8, 11 and / or 14; (xi) a nucleic acid sequence encoding an amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15; (xii) a nucleic acid sequence encoding an amino acid sequence with at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% sequence identity to the amino acid sequence of SEQ ID NO: 6, 9, 12 and / or 15.

18. A set of genetic markers for screening and / or identifying a cereal plant comprising an engineered alien addition chromosome according to any one of claims 1 to 8, or 17, or for screening, identifying, or mapping the engineered alien addition chromosome according to claims 16 or 17, or the chromosomal unit according to claims 5, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, marker L, marker M, marker N, marker O, marker P, marker Q, marker R, marker S, marker T, marker U, marker V, marker W, marker X, and / ormarker Y, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J and / or at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen or all fourteen marker(s) L, M, N, O, P, Q, R, S, T, U, V, W, X and / or Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively.

19. The set of genetic markers according to claim 18, wherein, with reference to the genotype deposited as NCIMB 44423, (i) marker A can be detected by a set of primers comprising or consisting of SEQ ID NO: 19 and SEQ ID NO: 20; (ii) marker B can be detected by a set of primers comprising or consisting of SEQ ID NO: 21 and SEQ ID NO: 22; (iii) marker C can be detected by a set of primers comprising or consisting of SEQ ID NO: 23 and SEQ ID NO: 24; (iv) marker D can be detected by a set of primers comprising or consisting of SEQ ID NO: 25 and SEQ ID NO: 26; (v) marker E can be detected by a set of primers comprising or consisting of SEQ ID NO: 27 and SEQ ID NO: 28; (vi) marker F can be detected by a set of primers comprising or consisting of SEQ ID NO: 29 and SEQ ID NO: 30; (vii) marker G can be detected by a set of primers comprising or consisting of SEQ ID NO: 31 and SEQ ID NO: 32; (viii) marker H can be detected by a set of primers comprising or consisting of SEQ ID NO: 33 and SEQ ID NO: 34; (ix) marker J can be detected by a set of primers comprising or consisting of SEQ ID NO: 35 and SEQ ID NO: 36; and (x) marker K can be detected by a set of primers comprising or consisting of SEQ ID NO: 37 and SEQ ID NO: 38, or for another genotype comprising the chromosomal unit as defined in claim 5, a homologous set of primers having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned primer SEQ ID NOs, respectively.

20. Use of a set of genetic markers according to claims 18 or 19 for screening for and / or for identifying a cereal plant comprising an engineered alien addition chromosome according to claims 1 to 8, or 17, or for screening, identifying, or mapping the engineered alien addition chromosome according to claims 16 or 17, or the chromosomal unit according to claims 5 or 17, wherein the set of genetic markers comprises at least one, preferably at least two of the markers selected from the group consisting of marker A, marker B, marker C, marker D, marker E, marker F, marker G, marker H, marker J, marker K, preferably wherein the set of markers at least comprises marker D, marker F, marker G and / or marker J, and / or at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen or all fourteen marker(s) L, M, N, O, P, Q, R, S, T, U, V, W, X and / or Y, wherein marker F is defined by SEQ ID NO: 108, marker G is defined by SEQ ID NO: 109, marker D is defined by SEQ ID NO: 110, and marker J is defined by SEQ ID NO: 111 and / or wherein markers L to Y are defined by SEQ ID NOs: 112 to 125, or a sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% sequence identity to any of the aforementioned SEQ ID NOs, respectively, alone or in combination with at least a set of primers specific for identifying at least one or a combination of gene(s) as defined in SEQ ID NOs: 1, 4, 7, 10 and / or 13.

21. Use of the set of genetic markers according to claim 18 for identifying a cereal plant having a misdivision rate of ≤ 1%, preferably a misdivision rate of ≤ 0.5%, more preferably a misdivision rate of ≤ 0.2% with respect to the male fertility restorer gene and the set of genes.

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