Creation Of DH Lines In Broccoli(Brassica Oleracea L.var.italica) And Cauliflower(Brassica Oleracea L.var.botrytis)

Broccoli(Brassica oleracea L.var.italica)and Cauliflower(Brassica oleracea L.var.botrytis)are two high-quality,high-nutrition vegetables in Brassica cabbage that use young curd as edible organs.Currently,most of the mainstream hybrid varieties of Broccoli and Cauliflower sold in the market rely on imports,and there are fewer varieties bred by independent innovation in our country,and their competitiveness are poor.Therefore,it is very important to breed high-quality hybrids with independent intellectual property rights.However,both Broccoli and Cauliflower are cross-pollinated crops.The prerequisite for breeding hybrids with strong heterosis and excellent traits is to obtain stable pure lines.Isolated microspore culture technology can solve this problem.In this study,20 Broccoli of different genotypes and Cauliflower of 6 different genotypes were used as materials to conduct microspore culture to obtain embryos,and then the cotyledon-shaped embryoid were subcultured,seedlings,and rooted.Ploidy identification will be carried out after transplanting,and the doubled haploid(DH)plants identified from Broccoli materials will be selfed,horticultural traits investigated,and excellent DH lines selected to provide materials for Broccoli breeding,Cauliflower material was cultured with microspores to obtain regenerated plants,and after ploidy identification,double haploid plants were obtained.The results are as follows:1.Genotype is one of the leading factors affecting embryoid formation in Broccoli microspore culture.Among the 20 donor materials,10 donor materials successfully obtained embryos.Among them,the embryo induction rate of ‘B4’ was the highest at 10.5embryos/bud;the embryo induction rate of ‘B8’ was the lowest,only 0.33 embryos/bud,The latter more has 10.17 embryos/buds.In terms of embryos regeneration and development,there are significant differences among the 10 genotypes of Broccoli.‘B8’ has the highest seedling rate among the 10 genotypes at 94.27% and the lowest seedling rate of ‘B7’ is57.24%.The difference is 37.03%.Different genotypes of Broccoli have different embryo development malformation rates.The highest is ‘B2’,which is 16.89%,which is 14.52%higher than the loregenerated plants all reached more than 80%,among which the transplant Broccoli 96.30%,the highest among the 10 genotypes.Through isolated microspore culture,620 regenerated plants were obtained.There were 335 double haploid plants.The averagedouble haploid rate was 54.03%,of which the highest was 73.44%(B1).The horticultural traits of the obtained DH lines were investigated.The DH lines with blue-green color,compact flower bulbs,uniform flower bud size,and non-hollow stems are the DH lines with the best comprehensive traits of ‘Y5’ and ‘Y8’.2.In the Isolated microspore culture of 6 different genotypes of Cauliflower,4genotypes were successfully obtained embryos and the embryo yield of 4 varieties of Cauliflower was significantly different,among which the embryo yield of ‘WB03’ was 9.67embryos/bud,‘WB01’ Only the globular embryos were obtained,and the embryo yield was only 0.16 embryos/bud.The embryo yield per bud in the former was 60.43 times of the latter.The experiment showed that the treatment with activated carbon added to the NLN medium had a significantly different effect on Cauliflower embryogenesis than the treatment without activated carbon,which did not obtain embryoid.In addition,the three genotypes of Cauliflower have differences in seedling formation.Among them,‘WB03’ has the highest seedling rate of 94.44%,and ‘WB04’ has the lowest seedling rate of 73.20%,and its mortality rate is 10.55%.The malformation rate of embryo development in ‘WB02’ was the highest at24.85%,while the malformation rate in ‘WB03’ Cauliflower embryo development was the lowest at 3.33%.Transplanting the regenerated plants of mature seedlings,the survival rate of Cauliflower transplanting is above 80%,and the survival rate of transplanting is the highest in ‘WB04’,which is 90.12%.The ploidy test of the regenerated plants of Cauliflower showed that there were 122 double haploid plants in the 306 regenerated plants,and the average double haploid rate was 39.45%.