30 results about "Diallel cross" patented technology

A method for breeding blue crab families comprises the following steps: S1, collecting blue crabs bred in different populations of China to construct base groups, and conducting genetic diversity comprehensive evaluation, S2, respectively selecting parent crabs from the different populations, establishing the families according to the complete diallel cross mode to grow larvae and breed in a standardizing mode, and calculating hybrid heterosis rates, S3, utilizing the crabs with outstanding hybrid heterosis to mate and combine, constructing the families through indoor artificial directional mating to grow the larvae and breed in the standardizing mode, and twice screening stocking families, S3, over-wintering mated female crabs of parent groups bred indoors of the stocking families, S4, selecting the parent crabs with high egg-laying rates from each family in following spring to grow the larvae and breed in the standardizing mode, and utilizing the breeding method to continue to screen the families. By means of the method for breeding the blue crab families, the growth rate and the survival rate of the blue crabs are used as indexes, blue crab families breeding is conducted, family economic characters are comprehensively evaluated, according to breeding results, blue crab norms are improved in the harvesting process, the breeding survival rate is improved, so that breeding benefits are greatly increased, and deviation caused by single character breeding is avoided.

The present invention discloses a breeding method for obtaining heterosis in lined seahorses, which comprises the following steps: S1, selecting parents of lined seahorse from populations with great differences in genetic background; S2, intensified rearing the parents before pregnancy; S3, matching and breeding the parents of lined seahorse from different geographical populations according to complete diallel cross method; S4, finely nursing pregnant seahorses; S5, respectively collecting all postlarvae (filial generations) hatched by each breeding group in one week; S6, rearing the filial generations; and S7, comparing survival rate and growth performance of filial generations. The present invention, via hybridization of different geographical populations to obtain lined seahorse, makes effective use of heterosis. Survival rate and growth rate of filial generations are apparently enhanced compared to that of those filial generations without hybridization. Such method enhances genetic diversity of lined seahorses and accelerates breeding of fine strain of lined seahorses.

A method for selectively breeding the crossed cabbage-type rape includes such steps as crossing between European rape ledos and Chinese rape Shuang No.2 to obtain sterile line, back crossing with Chinese rape Shuang No.2 to obtain non-micropollen sterile line and relative maintenance line, copmlex crossing to obtain restoring line, and diallel crossing to obtain Shanyou No.6 and No.8, which feature high yield.

The invention discloses a quantitative character gene pyramiding breeding method for pinctada fucata. The method comprises the following steps of: collecting at least three pinctada fucata groups from different sources, constructing F1 generation diallel crossing families, evaluating every each family after cultivating for one year, computing an average breeding value, and selecting families of which the breeding values are ranked at first 50 percent for serving as candidate families for constructing a core breeding family, wherein every each combination comprises at least ten families; screening female and male individuals from the candidate families, selecting female and male individuals which are ranked at first 100 places in sizes for measuring, computing individual breeding values, and sequencing; selecting female and male individuals with highest individual breeding values from families with highest female and male breeding values for mating respectively, selecting female and male individuals of which the individual breeding values are ranked at first places from families of which the female and male breeding values are ranked at second places for mating, and so on, and constructing an F2 generation core breeding family; and constructing multiple generations of families including F3, F4, F5 and the like according to the method for breeding generation after generation to over five generations. Through breeding according to the method, the genetic improvement of every each generation can be over 10 percent, the inbreeding coefficient can be controlled at a set level, and inbreeding depression is avoided.

The invention relates to a recurrent selection method for a dominant germplasm population of hybrid wheat. The recurrent selection method comprises the following steps: respectively carrying out half-sibling ear line phenotype recurrent selection on a CMS sterile line population and an R restoring line population; carrying out clustering analysis of genetic difference and heterotic group on diallel cross F1 combinations and parents thereof, wherein the parents comprise maintainer lines and restoring lines of male sterile lines CMS of wheat cells; carrying out CMS line half-slib recurrent selection by taking CMS sterile lines as female parents and B lines as male parents, selecting excellent sterile lines subjected to recurrent selection, and carrying out double haploid induction to obtainmale sterile DH lines; carrying out R line half-slib recurrent selection by taking dominant genic sterile Tal ear lines as female parents and R lines as male parents, selecting excellent sterile plants subjected to recurrent selection, and carrying out the double haploid induction to obtain fertile DH lines with restoring genes; carrying out test cross on the sterile DH lines and the fertile DH lines, selecting heterosis crosses of the lines according to the test cross result, and cultivating wheat hybrid varieties.

The invention provides a breeding method for inducing intersexual pelteobagrus fulvidraco to generate a super-male fish synthetic line and an all-female synthetic line. The breeding method comprises the steps of induction of gamete XY type intersexual fish and gamete XX type intersexual fish and criterions of gamete types, a test cross screening method that backcross of the XY type intersexual fish is utilized to generate a candidate super-male fish population and super-male fish, and a technology that backcross of the gamete XX type intersexual fish is utilized to generate the all-female synthetic line. According to the technology, for multiple geographical populations introduced according to the technical requirements, the super-male fish synthetic line and the all-female synthetic lineare constructed respectively, and a diallel crossing test is used for screening an all-female pelteobagrus fulvidraco production combination with hybrid vigors. The breeding method for inducing the intersexual pelteobagrus fulvidraco to generate the super-male fish synthetic line and the all-female synthetic line has the advantages that an electronic digital chip tag labeling management method isestablished in order to prevent population mixing and ensure the accuracy of test cross identification, the induced intersexual fish does not need genetic identification, a screened super-male familyhas high male rate, the requirements for instrument equipment are simple, the technology is easy to operate, and the breeding method is also suitable for breeding of all-male fish and all-female fishof other male gamete alien fish.

The invention provides a method for screening high-quality hybrid rice combinations and belongs to the technical field of rice breeding. According to the method, fragrant type high-quality parents aresubjected to incomplete diallel cross grouping, at high-temperature summer drought ecological selection pressure, Yuxiang 203 is adopted as a reference, a fragrant rice combination with excellent plant and leaf properties, good fecundity and good disease resistance can be screened, in addition, a combination of which the brown rice chalkiness and the chalky kernel percentage are prior to those ofthe reference is primarily screened through artificial husking, rice of the novel combination at a mature stage is finely processed, and a combination of which the head rice rate, the chalkiness, thee chalky kernel percentage and the transparency are prior to those of the reference is screened, so that high quality of the combination is ensured. By adopting the method, eating taste indexes of the refined rice are also screened, so that the obtained hybrid rice combination has the advantages of being good in appearance, good in taste and high in commodity rate, and high-quality breeding of hybrid rice in high-temperature summer drought regions can be achieved.

The invention discloses a field planting method for efficiently mating maize diallel crossing combinations. Male parents are planted in rows, wherein the male parents of the same row are the same male parent selfing line; female parents are planted in lines, wherein the female parents of the same line are the same female parent selfing line, the number of rows of each line of the female parents is equal to that of the types of the male parent selfing lines, the first row of the male parent selfing lines and the first row of all the lines of the female parent selfing lines are planted into one row, the second row of the male parent selfing lines and the second row of all the lines of the female parent selfing lines are planted into one row, and the rest can be done in the same manner until the last row of the male selfing lines and the last row of all the lines of the female parent selfing lines are planted into one row. During pollination, the female parent selfing lines are subjected to castration, the male parent selfing lines pollinate corresponding rows of female parent selfing lines by row in correspondence to the lines, and after the selfing lines are ripe, harvesting is sequentially conducted by row and by line. According to the field planting method, the workload and complicated degree in the preparing links of existing diallel crossing combinations are lowered, the probability of pollen mixing is lowered, the pollination and seed clearing efficiency is improved, errors caused by human negligence are reduced, and the field planting method is suitable for application and popularization of maize breeding within a large range.

The invention discloses a method for space mutation breeding of a maize strong heterosis cross combination parent. The method includes the steps of: using a recoverable satellite to carry a maize inbred line or hybrid; recovering the primary seed and conducting monoseeding without thinning out seedlings, and performing selfing totally; subjecting a first generation of selfing to ear row planting, first selecting a good ear row, then selecting a good single plant from the good ear row to undergo selfing; increasing the planting group of a second generation of selfing, increasing the selection pressure, and further carrying out optimum selecting from the best to perform selfing; for a third generation of selfing, employing diallel crossing to prepare a combination, and letting a mutant line undergo selfing continuously; and identifying the cross combination by multipoint planting, and selecting mutant strains with good comprehensive performance and the cross combination with high specific combining ability through combining ability analysis. By improving the prior art, the method provided in the invention shortens, improves the period of inbred lines, and accelerates breeding of new varieties.

The invention discloses a high-efficiency corn variety circulation breeding method. The method comprises the following steps: 1, selecting a first group of female parents and a first group of male parents in an area; 2, carrying out hybridization and 1-3 time directional backcrossing improvement on the first group of female parents and the first group of male parents to obtain an improved early selfing line material; 3, selfing the improved early selfing line for 2-4 generations to obtain a base material, selecting a representative key inbred line with good general combining ability, and carrying out incomplete diallel cross on the selected representative key inbred line and the base material; 4, screening a base material with good general combining ability through analysis, and selfing the screened base material used as a target early selfing line material for 4-6 generations to obtain a second group of female parents and a second group of male parents with good general combining ability; and 5, hybridizing the second group of female parents and the second group of male parents, respectively planting corn test cross combinations obtained through the hybridization in all regions, and carrying out yielding ability and disease resistance screening. The problems of low efficiency and large cost of high-yield corn cultivation in the prior art are solved.

The invention belongs to the technical field of cotton breeding, and provides a method for molecular marker-assisted breeding of extra-early-maturing cotton germplasm, which comprises the following steps: S1, collecting a cotton variety with at least one of early maturing, high yield, disease resistance and high quality as a high-quality resource library; S2, extracting DNA of each cotton variety,synthesizing an SRAP primer, and calculating a Jaccard similarity coefficient and carrying out clustering analysis by utilizing an SRAP molecular marker; s3, screening out candidate parents in combination with specific primer character identification; S4, grouping the candidate parents, carrying out an incomplete biserial hybridization test, and calculating general combining ability and special combining ability; s5, preparing a hybridized combination, and breeding to obtain a stable strain; and S6, detecting the early-maturing gene of the new strain by using the specific primers of the SSR molecular marker to obtain the early-maturing, high-yield, high-quality and disease-resistant strain. By means of the technical scheme, the problem that in the prior art, early-maturing cotton breedingefficiency is low is solved.

The invention discloses a method for breeding and producing a new variety of a commercial line of eriocheir sinensis. The method comprises the following steps: (1) parent selection of the commercial line: selecting commercial selection lines A and B of eriocheir sinensis for serving as parents; (2) production of the commercial line: performing diallel crossing on the commercial selection lines A and B to produce the commercial line; (3) screening of the commercial line: screening an A-female and B-male commercial line which takes line A as a female parent and takes line B as a male parent through growth contrast test; (4) performing productive verification on the commercial line; (5) applying the new variety of the commercial line. By adopting the new variety of the commercial line bred and produced through the method, the major advantages of the female parent A and the male parent B are well combined, high growth speed, high group yield and remarkable hybrid vigor are realized, and excellent provenance is provided for the river crab industry in China. The new variety is the first variety of the commercial line of eriocheir sinensis in China.

The invention relates to establishment of a dominant population of northern spring wheat, belonging to the technical field of selective breeding of plant varieties. The technology provided by the invention comprises the following steps: according to complicated relationships like blood relationship, genetic relationship and geographical relationship, dividing northern spring wheat varieties into two simple dominant populations, i.e., a population m and a population n, then selecting a plurality of improved varieties popularized in a proper wheat region and carrying out diallel crossing, and seeking a best combination (m and n) as a tester; subjecting breeder-owned key backbone resources to correspondingly cross-breeding with the population m and the population n, then carrying out field identification and variety testing, eliminating the combination with a yield lower than the yield of the tester, retaining the progeny combination cross-breeding with the population m with the yield higher than the yield of the tester and carrying out including into a group n, and retaining the progeny combination cross-breeding with the population n with the yield higher than the yield of the tester and carrying out including into a group m; respectively carrying out diallel crossing in the group m and the group n; then selecting a best combination from each group, and carrying out cross-breeding so as to create an ideal variety; meanwhile, using the created ideal variety as the tester in a second round for a next cycle. The main purposes for establishment of the dominant population of the northern spring wheat are to shorten the time of northern spring wheat breeding and realize early selection of an ideal main popularized northern spring wheat variety which is urgently needed in local.

An early generation association method for testing and choosing the three cytoplasmic male sterile lines of cabbage-type rape includes such steps as diallel crossing between the maintainer materials and restoring materials to choose the paired lines and reject the maintainer lines and restoring lines which have low combining ability, screening the maintainer materials by maintenance effect, screening the maintainer materials again by their interactive performance, and backcrossing between the chosen maintainer line to culture excellent sterile line As a result, three excellent lines are crossed to obtain the crossed rape with strong dominance.

The invention discloses a method for breeding an inbred line based on a corn Suwan-Iodent population. The method comprises the following steps: cutting seedlings of the population and selecting seedlings according to environmental stress pressure; conducting multi-environment remote identification and selection; obtaining a test cross variety by adopting an incomplete dicolumn hybridization design; conducting field identification; analyzing a heterosis mode; and evaluating and analyzing hybrid yield and field multipoint phenotypes, and breeding a selfing line. The method effectively solves a group photosensitivity of Suwan-Iodent corn, hasobvious advantages, strong operability and strong purposivenesscompared with the existing breeding method, particularly well solves a problem of photosensitivity selection of a tropical material in step one of cutting seedlings of the population and selecting seedlings according to environmental stress pressure, and provides a good possibility for utilization in a temperate zone.

The invention provides a breeding method of close-planting-resistant high-yield cabbage type rape hybrid varieties. The breeding method includes the following steps that existing n1 cabbage type hybrid rape sterile lines and n2 cabbage type rape restoring lines are used for incomplete diallel cross, and F1-generation hybrids are obtained; the F1-generation hybrids are subjected to a field randomized block multiplicating variety comparison cultivation test, obtained test varieties are subjected to grain yield measurement, and high-yield varieties with the yield increased by 5% or above are screened out; the obtained test varieties are subjected to harvest index measurement, and high-harvest-index varieties with the harvest indexes being 3.0 or above are screened out; the varieties meeting the yield increase and harvest index requirements at the same time are determined as high-yield cabbage type rape hybrid varieties; finally the F1-generation hybrids corresponding to the varieties are subjected to high-density planting, and the varieties with the plant save numbers larger than or equal to 80% of the final seedling number are screened out and determined as the close-planting-resistant high-yield cabbage type rape hybrid varieties. The method has the remarkable advantages of being high in product yield, high in applicability, high in universality and the like.