Genetic Resistance to Bean Leaf Crumple Virus Transmitted by Bemisia Tabaci (Hemiptera: Aleyrodidae)

Since 2002, snap bean (Phaseolus vulgaris) plantings in the Cauca Valley department of Colombia have been severely affected by Bean Leaf Crumple Virus (Begomovirus: Geminiviridae) transmitted by the biotype B whitefly, Bemisia tabaci. The virus-vector relationship was studied using common bean genotypes selected as potential sources of resistance. Transmission efficiency of the virus was determined using different numbers of adult insects, males and females, per plant. In the susceptible variety Top Crop, virus transmission was achieved by a single adult per plant and the proportion of infected plants increased with the number of adults per plant. Above 15 adults per plant, however, increase in the incidence of the virus was not significant. Males and females of B. tabaci biotype A were more efficient in transmission of the virus than those of biotype B. The genotypes evaluated exhibited different levels of resistance, with the black bean materials being the most resistant. The existence of sources of resistance to Bean Leaf Crumple Virus is confirmed, which will permit the introduction of genetic resistance to this virus in snap bean varieties grown in the Cauca Valley.