Evaluation of disease severity caused by Bean golden mosaic virus in different bean cultivars

Abstract

Common bean (Phaseolus vulgaris L.) can be affected by several viral diseases, including golden mosaic caused by the Bean golden mosaic virus (BGMV). When infected by BGMV, bean plants undergo major physiological changes, leading to a reduction or complete loss of productivity. This study aimed to evaluate and compare seven bean cultivars and lineages, as well as the legume calopo (Calopogonium mucunoides Desv.), for the severity of golden mosaic symptoms and BGMV titre following inoculation. The study was conducted in the greenhouse under controlled environmental conditions. Plants were inoculated with viruliferous whiteflies [Bemisia tabaci (Gennadius)], and evaluated for severity of disease symptoms at 7, 10, 15, 20, and 25 days after inoculation (DAI). The virus titre was measured by quantitative PCR (qPCR) analysis with primers specific for the virus coat protein gene. All bean genotypes were symptomatic for BGMV infection, but calopo was not. There were differences among the tested cultivars and lineages for the expression of symptoms. Differences in BGMV titre also were observed among the cultivars at 10 and 25 DAI. The bean cultivar ‘Tangará’ had a greater viral titre but exhibited lower symptom severity than the other cultivars. Calapo was tolerant to BGMV.