Genetics of Four Male‐Sterile, Female‐Fertile Soybean Mutants

Mutations affecting male cell and organ development may produce male‐sterile, female‐fertile plants that have application in plant breeding. In studies designed to test recombination frequencies and allelism, four such mutants were identified independently in soybean [ Glycine max (L.) Merr.] populations that were characterized by chromosomal instability. The objectives of this study were to determine the inheritance of these four mutants and to test allelism with the seven known male‐sterile, female‐fertile soybean mutants. Allelism tests were done with male‐sterile, female‐fertile plants as female parents and known heterozygotes as male parents. All four mutants were inherited as single recessive nuclear genes. Male‐sterile mutants (MSM)‐1, MSM‐2, MSM‐3, and MSM‐4 were nonallelic to each other. Mutants MSM‐1, MSM‐2, and MSM‐3 were nonallelic to known mutants. They were assigned Genetic Type Collection numbers T357H, T358H, and T359H and the gene loci were assigned the symbols Ms7 ms7, Ms8 ms8, and Ms9 ms9 , respectively. Mutant MSM‐4 was allelic to T259H ( Ms2 ms2 ) and was designated T360H Ms2 ms2 (Ames). The T259H Ms2 ms2 mutant becomes T259H Ms2 ms2 (Eldorado). Dehisced anthers from MSM‐1 and MSM‐4 were similar in phenotype. Aborted pollen grains of MSM‐2 and MSM‐3 were different in phenotype from each other and from the seven known male‐sterile, female‐fertile soybean mutants. These four independently derived male‐sterile, female‐fertile mutants could be used in plant breeding to produce hybrid seed.