The Dark Corona Character in Seedcoats of Common Bean Cosegregates with the Pink Flower Allele vlae

Abstract

Crosses were made with two common bean (Phaseolus vulgaris L.) parents that have pink flowers (vlae/-) and mineral-brown seedcoats with dark corona, viz., vlae BC3 5-593 (derived from Lamprecht V0491) and F3 vlae dark corona (derived from Lamprecht M0048). The third parent v BC2 5-593 had white flowers (v/v) and mineral-brown seedcoats without dark corona (derived from Lamprecht M0056). The F2 progenies of the crosses v BC2 5-593 × vlae BC3 5-593 and F3vlae dark corona × v BC2 5-593 segregated for only two phenotypic classes: either pink flowers and seeds with dark corona or white flowers and seeds without dark corona. Thus, it was demonstrated that the dark corona character (Cor) is either tightly linked to vlae (<4 map units) or is a pleiotropic effect of vlae. Pleiotropy is more probable, but tight linkage cannot be ruled out. A linkage of 15 map units between Cor and R (currently, R is known to be tightly linked with C) reported by Lamprecht was not found by subsequent authors, and the linkage map of common bean should be revised accordingly, i.e., no linkage exists between V (Cor) and C.