Regresar

Transmission of the begomoviruses TYLCV and TOVEV to tomato commercial genotypes by bemisia tabaci (Gennadius) (hemiptera: Aleyrodidae)

Abstract:

The begomovirus-Bemisia tabaci (Gennadius) complex is the main sanitary problem of tomatoes in Venezuela. Genotypes resistant to begomoviruses are a valuable alternative for integrated management of this problem. Consequently, it was assessed the performance of the cultivars Rio Grande (CRG), Alba El cid and Shan TY, the first one susceptible and the other three promoted as resistant to TYLCV. This virus, along with ToVEV, are two common tomato begomoviruses in Venezuela. Transmission assays mediated by B. tabaci were conducted to assess time for symptoms appearance and transmission efficiency. CRG showed TYLCV symptoms after 12.6 ± 1.2 days post inoculation (DPI) in 100 % of the plants, while for the remaining cultivars it ranged from 14.1 ± 1.3 to 16 ± 1.5 DPI with 18.5-33.3 % of symptomatic plants, generally with mild symptoms. With ToVEV for CRG, symptoms appeared at 12.4 ± 1.2 DPI with 100 % of affected plants, and for the other cultivars more than half of the plants (ranging 66.7 to 81.5 %) showed symptoms at 12 ± 1.1 to 14.9 ± 1.4 DPI. El Cid showed the most severe symptoms. In all plants exposed to begomovirus, viral DNA was detected by PCR. The resistance to a begomovirus can provide some resistance to another but not to all of them. However, those that showed tolerance could be utilized to reduce the effect of these begomoviruses on tomato crops in Venezuela.