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

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 l(ers) 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 l(ers) was a different allele at J. We propose the gene symbols J (formerly 1), j (formerly L), and j(ers) (formerly l(ers)). The seedcoat genotype of 'Thuringia' was found to be t P C z j g b v(lae) rk(d). A new seedcoat pattern called reverse margo was found to be determined by the genotype T/t z/z j/j(ers) 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 F-2 population segregating for j vs. J in a t z genetic background, i.e., from the cross t z j x t z J in BC1 to 5-593. The linkage distance between marker OL4(525) and j was determined to be 1.2 cM. In a population segregating for J and j(ers), the distance between the marker and j(ers) was determined to be 4.7 cM. The utility of marker OL4(525) is limited primarily to the Middle American gene pool.