Effect Analysis On Inducing Male Sterile Lines And Maintainer Lines By Double Haploid Y3560 And Y3380 Inducer In Brassica Napus L.

Double haploid is an important breeding materials in Brassica napus and it can be mainly obtained by isolated microspore culture.But the method is limited by a number of factors,such as genotype and so on.The Academy of Agricultural and Forestry Sciences of Chengdu has bred two special materials “Y3560” and “Y3380” over the past few years,which were named double haploid inducer of Brassica napus,because they can induce rape female parent to produce double haploid offspring.In this study,two inducers were used as the male parents,and Pol CMS and Ogu CMS and their maintainer lines as the female parents.The inducing results will be analyzed by flow cytometry,fertility identification,SSR molecular marker and SNP chip technology.The growing processes of embryos and siliques will be observed.The study preliminarily explored the induction mechanism of Y3560 and Y3380,and the certain theoretical basis for the two inducers applying in breeding and creating new materials of Brassica napus would be established.1.The ploidy of the pollinated progenies seedlings were detected by flow cytometry The ploidy of all the progenies was the same with female parents,and they were tetraploid rape.The results showed that 3 F1 progenies from 0068A×Y3560,0933A×Y3560 and Shuang717A×Y3560 respectively contained 6,2 and 1 fertile plant.The mother parents were CMS,and so these plants could be inferred to be F1 hybrids.The inducer rate of double haploid was 70%-100%.2.4 progenies from 0068A(ogu CMS)×Y3380 were identified by SSR molecular marker technology.The results showed that 2 plants were hybrid because of containing the band from their female and male parents.3.F1 progenies were analyzed by using the SNP array.The results indicated that both of the inducers could induce stable and homozygous double haploid,and the induction rate was between 16.67% to 83.33%.Comparing the methods of identifying the F1 progenies,flow cytometry,fertility phenotype observation and SSR molecular marker technology could only identify few true hybrids,which could not be the main approaches of identification.Based on above analysis,the most accurate method was SNP array technology.4.The results of SNP array analyses showed that within the F1 hybrids,there was a great difference in the joining probability of paternal gene between the two induced lines,and the joined rate ranged from 19.17% to 42.49%.Within the induced double haploid,there was a little phenomenon of paternal gene infiltrating,and the ratio was between 0.01% and 5.33%.5.Comparing the efficiency of the two inducers on different materials,the results indicated that the inducing rate of Y3650 and Y3380 on isonuclear alloplasmic female parents was obviously different.The order was fertile cytoplasm>polima cytoplasm>radish cytoplasm,and it showed that there was an obvious interaction between the induction efficiency and the cytoplasmic type of female parents.When the nuclear gene of the female parents were the same,the differences of induction were mainly influenced by the cytoplasmic genes,and when the cytoplasm gene was the same,the differences were mainly affected by nuclear gene,which indicated that there was obvious nucleo-cytoplasmic interaction on the inductive effect.The ability of the two induction lines was more stable on inducing the pol CMS.6.Using the two inducers to pollinate Brassica napus,the embryos became withered at about 19 d,and a large number of embryos died successively about 7 days later,and few embryos could develop into normal seeds,indicating that there was an obvious abnormality in embryo development after pollination by the inducers.