Flower Colors in Common Bean Produced by Interactions of the Sal and V Loci and a Gametophyte Factor Ga Linked to Sal

Abstract

Inheritance of red flower color was investigated in crosses using Lamprecht's lines M0169 and M0056, which are derived from Phaseolus coccineus L., and Univ. of Florida P. vulgaris L. breeding line 5-593. Based on segregation in the F2populations from 5-593 × M0169 and 5-593 × M0056, we hypothesize that the genotypes for flower colors are sal/sal V/V for 5-593 and Sal/Sal v/v for M0169 and M0056. The backcross 5-593 × F, (5-593 × M0056) segregated for four flower colors in about equal frequencies, and F2, F3, and F4progeny tests of the backcross plants provided confirmation of all the genotypes in the digenic model. The two recombinant true-breeding colors/genotypes were white (sal/sal v/v) and china rose (Sal/Sal V/V). We hypothesize that the large deficiency of plants carrying the Sal allele in segregating populations is due to a gametophyte factor linked to Sal. We propose the gene symbol Ga for the gametophyte factor locus, which achieves complete selection for pollen carrying Ga on female plants carrying Ga, i.e., no pollen carrying ga achieves fertilization. The linkage between Ga and the marker locus Sal is 17 CM (centiMorgan).