THE GRISEOALBUS (GRAY-WHITE) SEED-COAT COLOR IS CONTROLLED BY AN ALLELE P(GRI) AT THE P-LOCUS IN COMMON BEAN

A cross was made between gri (gray-white seedcoat) and p (pure-white seedcoat) using genetic stocks gri BC(2)5-593 and p BC(2)5-593 developed to carry only a single recessive allele for seedcoat color in an otherwise all-dominant genetic background. The recurrent parent, 5-593, is a Florida dry-bean breeding line with bishops-violet flowers, determinate habit, small seed size, shiny black seeds, and seedcoat genotype T Mar P [C r] D J G B V Rk. The F1 progeny from the above cross between gri and p had the flower color pattern and seedcoat color of the griseoalbus character (gri), but had less intense color expression. Therefore, I hypothesized that gri is an allele at the P locus (allelic interaction). The hypothesis of allelism was confirmed in the F2, which failed to segregate for bishops-violet flowers and black seed, i.e., no complementation was evident. The symbol p(gri) is proposed for the new allele at P, where the dominance series is P > p(gri) >p. The gene for gray-white seeds in gri BC(2)5-593 was shown to be allelic to Lamprecht's gri gene in V0059 (PI 527716).