The preliminary location study on the fertility restorer genes for cytoplasmic male sterility (CMS) in alfalfa

In this study, alfalfa CMS MS-GN-1A was used as the female parent, and the restorer line MS 178 was used as the male parent to construct BSA separate groups. All products of F1 were male fertile. There were 221 plants in the F2, and the number of sterile plants was 57, with 164 fertile, and no semi-sterile plants were found. Based on the results of the fertility microscopy, the separate population was divided into two groups, fertile and sterile group; the genomic DNA of the fertile and sterile groups were extracted and 20 samples of DNA from each group were randomly selected and mixed into a fertile and sterile gene pool for the positioning of restoring genes. The experiment randomly selected 160 pairs of known tetraploid alfalfa SSR primers. To amplify the gene pool DNA, two molecular markers with polymorphism (Mt2c12 and AW166) were obtained, and were initially positioned on a composite of five primers. All primers on this group were synthesized, and the designed primers were screened again. Finally, four markers with polymorphism were obtained: BI68, Mt2c12, BG267 and AW776153, with a genetic distance of 19.0 cM, 20.9 cM, 44.6 cM, and 72.1 cM, respectively.