Efficiency of Bemisia tabaci (Gennadius) populations from different plant-hosts for acquisition and transmission of cotton leaf curl virus

Whitefly (Bemisia tabaci) populations collected from five crop plants, viz brinjal, cotton, potato, tomato, soybean and a weed, Sida sp., and maintained on respective host plants were studied for virus acquisition from diseased cotton plant and its subsequent transmission to healthy cotton plants. The presence of virus in whitefly and diseased plants was established by PCR amplification of CLCuV-specific DNA primers (P1800-500). The virus acquisition from the diseased cotton plants as well as its transmission to healthy cotton plant to cause disease was 100 per cent in the case of cotton-specific whitefly. Compared to this, using whitefly from other host-plants, both the values for acquisition of virus as well as its subsequent transmission decreased, being higher with soybean-specific whitefly (80 and 70%, respectively) and minimum with tomato whitefly (20% each). However, the actual virus transmission efficiency (ATE), when expressed after taking into account the fraction of whitefly samples that did not acquire virus, though was found to be 100 per cent in the case of cotton-, tomatoand brinjal-whitefly, it remained more than 67% with whitefly from other crops/weed. The study revealed that whitefly populations that are specific to different host-plants, differ primarily in their efficiency for acquiring CLCuV and once the virus is acquired it is efficiently transmitted to healthy cotton plants to cause cotton leaf curl disease (CLCuD). The results hold significance in control of CLCuD through appropriate management of whitefly on alternate host plants/weeds, both in and around the cotton growing areas.