Inheritance of Reverse Margo Seedcoat Pattern and Allelism between the Genes J for Seedcoat Color and L for Partly Colored Seedcoat Pattern in Common Bean

Abstract

Two common bean (Phaseolus vulgaris L.) genes, J (modifies seedcoat color and pattern) and L (modifies partly colored seedcoat pattern), were tested for allelism using genetic tester stocks. Those stocks have a common genetic background by backcrossing to the recurrent parent, Florida dry bean breeding line 5-593, that has black self-colored seeds and purple flowers due to the genotype T P [C r] Z J G B V Rk. Specifically, the L gene from `Thuringia' and the lers gene from `Early Wax' were tested for allelism with the j gene from various genetic tester stocks. L was found to be identical with j, but lers was a different allele at J. We propose the gene symbols J (formerly l), j (formerly L), and jers (formerly lers). The seedcoat genotype of `Thuringia' was found to be t P C z j g b vlae rkd. A new seedcoat pattern called reverse margo was found to be determined by the genotype T/t z/z j/jers in a P C G B V genetic background. A randomly amplified polymorphic DNA marker was developed for the j gene (formerly L) from `Thuringia' using bulk segregant analysis in an F2 population segregating for j vs. J in a t z genetic background, i.e., from the cross t z j × t z J in BC1 to 5-593. The linkage distance between marker OL4525 and j was determined to be 1.2 cM. In a population segregating for J and jers, the distance between the marker and jers was determined to be 4.7 cM. The utility of marker OL4525 is limited primarily to the Middle American gene pool.