Two genes from Phaseolus coccineus confer resistance to bean golden yellow mosaic virus in common bean

Abstract

Bean golden yellow mosaic virus (BGYMV), incited by a whitefly (Bemisia tabaci Gennadius) transmitted geminivirus, is an important disease that can limit common bean (Phaseolus vulgaris L.) production in Central America, the Caribbean, and southern Florida. Only a few genes are currently deployed in BGYMV-resistant common bean cultivars. The identification of novel sources of resistance would help bean breeders broaden the genetic base of resistance to this important virus. Phaseolus coccineus L. germplasm accession G35172 was found by International Center for Tropical Agriculture scientists to be resistant to BGYMV. Populations derived from an interspecific cross between P. vulgaris and P. coccineus were evaluated to study the inheritance of resistance to BGYMV. Segregation ratios of F2 plants and other populations suggest that BGYMV resistance from P. coccineus is controlled by two genes. A recessive gene, with the proposed symbol bgm-3, confers resistance to leaf chlorosis and a dominant gene, with the proposed name Bgp-2, prevents pod deformation in the presence of BGYMV. Results from allelism tests with previously reported BGYMV resistance genes (bgm, bgm-2, and Bgp) and the absence of the SR-2 sequence-characterized amplified region marker for bgm support the hypothesis that bgm-3 and Bgp-2 are different genes for BGYMV resistance.