The Preliminary Location Study On The Restoring Genes For Cytoplasmic Male Sterility (CMS) In Alfalfa

In this study,the cytoplasmic male sterile lines MS-GN-1A,and the excellent restorer lines MS178 were used as parents to cultivate F2 and near isogenic lines of restoring gene,by hybridization and forced selfing.Through investigation and analysis the sterility of F2 population and F1,confirm the genetic pattern of fertility restoring genes of alfalfa cytoplasmic male sterile;Using two groups of materials,the SSR molecular markers and BSA were used to screen and restore the molecular markers of genes linkage,and Rf gene was genetically mapped.The results of the experiment are as follows:(1)In this study,alfalfa CMS MS-GN-1A was used as the female parent,and the restorer lines MS178 was used as the male parent to construct of BSA separate groups,all performances of F1 were male fertile,fertile pollen rate of 100%,F2 were found to be sterile and fertile type in microscopic examination at the time of flowering;There were 221 plants in the F2,and the number of sterile plants were 57,and 164 were fertile,no semi-sterile plants were found,the separation ratio of fertility and sterility is 3:1,belonging to the typical single gene control of sporophytic infertility.(2)Based on the results of fertility microscopy,the Separate population was divided into two groups,fertile and sterile group;the genomic DNA of fertile and sterile groups were extracted respectively,each group randomly selected 20 samples of DNA were mixed as fertile and sterile gene poolfor the positioning of restoring genes.The test by using 40 SSR primers amplify DNA gene pool,three molecular markers with polymorphism were obtained,Mt2c12,AW166,Respectively,Initially positioned on composite5.All primers on this groups were synthesized,the designed primers were screened again.Finally,four markers with polymorphism were obtained,BI68?Mt2c12?BG267andAW776153?Genetic distance is,19.0cM,20.9 cM,44.6 cM,72.1cM,respectively.