Allelism tests involving two genes, ers and ers-2, that restrict partly colored seedcoat expression in common bean

An inheritance study was conducted with genetic stocks constructed in the genetic background of the recurrent parent 5-593, a Florida dry bean (Phaseolus vulgaris L.) breeding line with black seeds and purple flowers and genotype PTZl(+). The genetic stocks, t ers ers-2 BC3 5-593 (pure white seeds), t virgarcus BC3 5-593, and t BC2 5-593 self-colored were constructed by backcrossing selected recessive alleles for partly colored seedcoats into 5-593. The cross t ers ers-2 BC3 5-593 xt BC2 5-593 self-colored was studied in F-1, F-2, and F-3. The observed data supported the hypothesis that ers is a synonym for z and that ers-2 is a synonym for a new allele (l(ers)) at the L locus. The cross t ers ers-2 BC3 5-593 xt virgarcus BC3 5-593 was studied in F-1 and F-2 progeny, and the results confirmed the hypothesis of allelism between ers and z, 'Thuringia' (pure white seedcoats) with genotype PtzL was crossed with t ers ers-2 BC3 5-593, t virgarcus BC3 5-593 and t BC2 5-593 self-colored. The cross 'Thuringia' (PtzL) xt ers ers-2 BC3 5-593 was studied in F-1 and F-2 and supported the hypothesis that l(ers) is an allele at L. The results of the other two test crosses are discussed, The gene ers-2 is a new recessive allele at L, for which the new symbol l(ers) is proposed. Thus, the dominance order at the L locus is L > l(+) > l(ers), where It is the null allele at L found in 5-593. The l(+) allele does not restrict the colored area of a partly colored seedcoat and is hypothetically the wild-type allele at L.