Molecular mapping of four ovule lethal mutants in soybean.

We report genetic mapping of four soybean ovule lethal mutants, PS-1, PS-2, PS-3, and PS-4, which had been identified as female partial-sterile mutants from a gene-tagging study. The four mutants had been classified into two mutation classes: (1) PS-1-sporophytic mutation affects sporophytically expressed genes; and (2) PS-2, PS-3, and PS-4 mutants-female gametophyte-specific mutations affect gametophytically expressed genes and are transmitted through the male, but not the female gametes. Molecular mapping demonstrated that these four mutant genes and previously reported female-partial sterile gene, Fsp1, are located independently on soybean molecular linkage groups (MLG-) using SSR markers. PS-1, designated as Fsp2 and Genetic Type Collection number T364, is located between SSR markers Satt170 and Satt363 on MLG-C2 and linked by 13.9 cM and 12.1 cM, respectively. PS-2, designated as Fsp3 and Genetic Type Collection number T365H, is located between SSR markers Satt538 and Satt429 on MLG-A2 and linked by 13.3 cM and 25.4 cM, respectively. PS-3, designated as Fsp4 and Genetic Type Collection number T366H, is located on the terminus of MLG-F and linked to Sat 152 by 13.1 cM. PS-4, designated as Fsp5 and Genetic Type Collection number T367H, is located between SSR markers Satt324 and Satt138 on MLG-G and linked by 19.6 cM and 7.5 cM, respectively. SSR markers adjacent to Fsp3, Fsp4, and Fsp5 were distorted from a 1:2:1 ratio and fit a 1:1 ratio. The segregation distortions of SSR markers adjacent to Fsp3, Fsp4, and Fsp5 are in support of male, but not female transmission of the Fsp3, Fsp4, and Fsp5 gametes.