Genetics and Cytology of a New Male-Sterile, Female-Fertile Soybean Mutant

摘要

Mutants affecting male sterility have potential applications in breeding methodology studies and for commercialization of hybrids. Male-sterile, female-fertile soybean [Glycine max (L.) Merr.] plants were observed in an F2 entry. Our objectives were to determine the inheritance, linkage, and allelism of the A94-JB-124 male-sterile, female-fertile mutant, and to conduct a detailed comparative microscopic study of microsporogenesis and microgametogenesis of fertile and sterile plants. The A94-JB-124 male-sterile, female-fertile mutant is a single recessive gene, allelic to ms6, and is linked to the W1 (flower color locus) with 4.3 ± 0.3% recombination value based on 988 F2 plants in the couplinglinkage phase. A comparative microscopic study of microsporogenesis and microgametogeucsis of fertile and sterile plants was conducted. The expression of the male-sterile gene is associated with rapid degenerative changes both in the tapetum and the parietal layer. These changes are initiated at the late sporogenous mass stage. The A94-JB-124 mutant was assigned gene symbol Ms6 ms6 (Ames 2) and Genetic Type Collection number T354H. The T295H Ms6 ms6 mutant is now designated Ms6 ms6 (Ames 1). T354H will be useful in the Coscgregation Method to produce hybrid soybean seed.