Abstract: 【Objective】 Dominant genic male sterility (DGMS) in Brassica napus is gaining importance in breeding program and utilization of heterosis. The multiple allele inheritance model has been characterized recently by analyzing the allelism between the male sterility allele (Ms) in 609A and the fertility restoration allele (Mf) in 609B as well as the alleles from several restorers tested. The present study was designated to provide further validation of the result with more restorers and another DGMS line. 【Method】Extensively screening was made through crossing 609A with parental materials, and the restored F1 s were subjected to allelism analysis with temporary maintainer test methodology. The fertile plants in Rs1046AB were crossed with temporary maintainers and the fertile plants in the subsequent progenies were selected to be selfed and backcrossed. The analysis of allelism between the two sterile lines was completed through testing the allelism between the Ms in 609A and the Mf in Rs1046B. 【Result】Twenty eight restorers for DGMS in 609A were screened out, out of which 15 were tested for allelism. All the alleles from the restorers tested were identified as being allelic to the Ms in 609A, because the testcross populations segregated in an expected 1﹕1 ratio for multiple allele inheritance model rather than the expected ratio of 3:1 for the digenic interacting model. Thus, the multiple allele inheritance model for DGMS was further confirmed. Meanwhile, crossing Rs1046B with maintainers produced F1s segregating in a ratio of 1﹕1, and there were only fertile plants in the selfed and backcrossed populations, which clearly indicated that Mf is allelic to Ms. Accordingly, Rs1046AB was demonstrated to inherit in the same way with 609AB. The restorer allele from Rs1046B restored 609A and the testcrosses made between the F1 and maintainers segregated in a ratio of 1﹕1, showing the restorer allele was allelic to Ms in 609A. 【Conclusion】Both of the sterile lines are conditioned by a locus with three alleles and the two Ms are allelic to each other. The genotypes of the sterile plants and fertile plants in the sterile line are MsMs and MsMf, respectively.

Key words: Brassica napus, Dominant genic male sterility, Multiple allele inheritance, Allelism analysis