Creation Of Brassica Ogura CMS BC₁ Generation Fertility Restoration Material By Embryo Rescue

In order to cultivate the Ogura CMS fertility restoration material of cabbage,the recovery gene of Brassica napus L.can be transferred into cabbage by the method of distant hybridization combined with embryo rescue.In this study,the fertility restoration materials of Brassica napus L.had been obtained,but the genetic background of Brassica napus L.was still present in these materials.It is still necessary to double back the interspecific hybrids to reduce the genetic background of rapeseed.In this experiment,the F1 generation of Brassica napus L.was used as the male parent,and the male sterile line of the cabbage Ogura was used as the female parent,and the two were sexually crossed;Embryo rescue was performed on the ovule by B5solid medium,and the BC₁ generation plants were cultivated,and the most suitable time for the BC₁ generation embryo rescue,the medium addition component and the best hybrid combination were screened out;The authenticity of BC₁ plants was identified from two aspects.On the one hand,ploidy identification was performed by flow cytometry;on the other hand,molecular markers were used for identification.This study draws the following conclusions:1.36 triploid F₁ hybrid plants were doubled at different concentrations and times by colchicine.Among them,the concentration of colchicine was 2.5 g/L,and the treatment time was 2 d;2.A total of 61 hybrids were obtained after ovule culture in vitro.The ovule in vitro culture was the highest in the seedling rate of 14 days after pollination,the composition of the medium was B1?NAA 0.05mg/L+TDZ 0.2mg/L+MT 0.5 mg/L?,and the hybrid combination was MS15×RFO-32.A total of 61 BC1 plants were obtained.Choosing a suitable hybridization combination,medium composition and time of seeding can promote the seedling rate of young embryos;3.The results of ploidy identification by flow cytometry showed that the peak fluorescence intensity of G1 phase of 44 BC₁ seedlings was 220,and the corresponding abscissa position was about twice the peak of the fluorescence of cabbage parents.Therefore,44 BC₁ hybrid seedlings were presumed to be Tetraploid plant;The specific bands were amplified by the molecular markers on the parents and tetraploid hybrids.The specific bands of the 38 tetraploid hybrids were consistent with the male parent,indicating that they had a restorer gene.4.38 embryos of Ogura CMS BC₁ generation fertility restoration materials were successfully created by embryo rescue.The best breeding techniques of cabbage BC₁embryo rescue and hybrid strain identification were screened.