Marker-assisted analysis for soybean hard seededness with isozyme and simple sequence repeat loci

Abstract

We determined the genomic regions of wild soybean (Glycine max subsp. soja) carrying quantitative trait loci (QTL) for hard seededness, a distinct character between the wild and cultivated soybeans. The segregation of hard seededness, as evaluated using seed coat permeability (SCP), was examined in the progeny of a cross between wild and cultivated soybeans. The high parent-offspring correlation coefficient between F2 and F3 indicated that SCP was a highly heritable character. A marker-assisted analysis of five isozyme and 131 simple sequence repeat (SSR) loci revealed that at least two major and one minor QTL were involved in controlling the trait. The QTL near an SSR marker (Satt459) in molecular linkage group D1b + W had the greatest effect on SCP, and accounted for 23.8 and 38.5% of the phenotypic variance observed in the F2 and F3 mean, respectively. Seed coat color, determined by a locus inhibiting seed coat color (7) and a pubescence color locus (7), was also closely associated with SCP in F 4 to F6, although seed coat color did not appear to be associated with SCP in the F2. The results of this and a previous study suggest that different sets of QTL contribute to the phenotypic difference of seed coat permeability in wild and cultivated soybeans to different degrees.