Studies on Genetic Male-Sterile Soybeans

Abstract
Soybean (Glycine max [L.] Merr.) germplasm, isogenic except for loci controlling male-sterility (ms1) and nodulation (rj1) was utilized to investigate the effects of reproductive tissue development and nitrogen source on the initiation of monocarpic senescence. The experimental genotypes (Ms1Rj1, Ms1rj1, ms1Rj1, and ms1rj1, were selected from a cross between N69-2774 and N59-5259, and were inbred to the F5 generation. Green-house-grown plants were collected during the period of flowering (77 days after transplanting) until maturity (147 days after transplanting). Leaf tissues from the respective genotypes were analyzed at the various harvest dates for RNA, phenolic, and chlorophyll concentrations; acid protease activity; polypeptide banding patterns of chloroplast thylakoids; and chloroplastic ultrastructure.