30 results about "Diallel cross" patented technology

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 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.

The invention discloses a breeding method for convergent improvement of carotene and dry rate characters of sweet potato, belonging to the technical of breeding of varieties of crops. The breeding method comprises the steps of: screening breeding parents; determining a male parent and a female parent and designing incomplete diallel cross; screening an optimal parental combination; and screening a breeding target variety. The breeding method is short in breeding period and high in speed; and the content of the carotene is increased, the dry rate characters are improved, the constant restraint of the breeding of the sweet potato by the remarkable negative correlation characteristic of the content of the carotene and the dry rate is broken through, the content of the carotene reaches 8-10mg / 100g, the dry rate reaches 28-30 percent or the dry rate reaches 32-36 percent and the content of the carotene reaches 1-5mg / 100g, and thus the improvement of the quality of the sweet potato is effectively promoted. The breeding method can be popularized and applied to the breeding of the sweet potato.

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 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.

The invention provides a parent selection method for breeding of weak gluten wheat. The method comprises the following steps: selecting n good weak gluten wheat varieties, preparing n(n-1) / 2 hybrid combinations according to the Griffing diallel crossing method II, separately planting each combination in a region and sparsely planting enough plants to obtain F1; planting genotypes of each F1 seed and parent seeds, altogether n(n-1) / 2+n genotypes, in a field according to random block permutation and harvesting seeds F2 in each region; determining protein content of sample grains and retention capacity of sample aqueous solutions; and analyzing general combining ability and special combining ability of protein content and aqueous solution retention capacity of F2 samples according to the model I of the Griffing method 2 and evaluating the utilization values of the parents and the combinations according to the general combining ability and special combining ability. According to the invention, parent and F2-generation seeds are used to research two quality characters closely related to the quality of weak gluten wheat and parents with optimal general combining ability are evaluated and selected according to the value of combining ability of protein content and aqueous solution retention capacity of each parent seed, so a theoretical basis is provided for reduction in blindness in parent selection of weak gluten wheat and for cultivation of new varieties of weak gluten wheat.

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 producing supermale and all-female mating lines by inducing yellow catfish facultative fish, including: XY genotype and XX genotype facultative fish induction and type judgment criteria, using XY genotype Facultative fish backcross to produce candidate supermale fish population and supermale fish testcross screening method, using the technology of XX genotype facultative fish backcross to generate all-female mating line. According to the above-mentioned technology, for multiple geographical populations introduced according to the technical requirements, super male and all female mating lines were respectively constructed, and the production combination of all male yellow catfish with hybrid advantage was screened out by diallex hybridization test. In order to prevent population mixing and test cross identification accuracy, the present invention establishes an electronic digital chip labeling management method, the induced facultative fish does not need genetic identification, the screened super-male family has the characteristics of high male rate, and the requirements for equipment are simple. The technology is easy to operate, and is also applicable to the breeding of all males and all females of other male dimorphic fishes.

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.

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.