Molecular mapping of 2 environmentally sensitive male-sterile mutants in soybean

In soybean [Glycine max (L.) Merr.], manual cross-pollination to produce large quantities of hybrid seed is difficult and time consuming. Identification of an environmentally stable male-sterility system could make hybrid seed production commercially valuable. In soybean, 2 environmentally sensitive male-sterile, female-fertile mutants (ms8 and msp) have been identified. Inheritance studies showed that sterility in both mutants is inherited as a single gene. The objectives of this study were to 1) confirm that msp and ms8 are independent genes; 2) identify the soybean chromosomes that contain the msp and the ms8 genes using bulked segregant analyses (BSAs); and 3) make a genetic linkage map of the regions containing these genes. Mapping populations consisting of 176 F(2) plants for ms8 and 134 F(2) plants for msp were generated. BSA revealed that Sat_389 and Satt172 are closely associated markers with ms8 and msp, respectively. Map location of Sat_389 suggested that the ms8 gene is located on chromosome 7; molecular linkage group (MLG) M. Map location of Satt172 indicated that the msp gene is located on chromosome 2 (MLG Dlb). Genetic linkage maps developed using F(2) populations revealed that ms8 is flanked by a telomere and Sat_389 and msp is flanked by Sat_069 and GMES4176. The region between the telomere and Sat_389 is physically 160 Kb. Soybean sequence information revealed that there are 13 genes present in that region. Protein BLASTP analyses revealed that homologs of 3 of the 13 genes are known to a play role in cell division, suggesting putative candidates for ms8.