Department of Plant Pathology, University of Agricultural Sciences, GKVK, Bangalore.
Abstracts of Research Papers Presented during the National Symposium of Indian Virological Society at Unit of Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110 012, October 14–1.
The B biotype of Bemisia tabaci which was detected in Kolar district of Karnataka state during 1999, was thought to have been introduced as immatures through various ornamental plant cuttings imported from other countries by floriculture industries located around Bangalore. The B biotype that has arrived in India appeared to have some resistance to common insecticides. In this study the B biotype was distinguished from the existing indigenous B. tabaci based on esterase activity and profiles. Qualitative and quantitative differences in esterases were observed between the biotypes. Esterase activity in individual B biotype adult whitefly was found 2–3 times higher than that of Indigenous strain. The esterase banding patterns were considerably variable for the first two densely stained slow moving bands (RF = 0.19 and 0.23) of B biotype and the two equally sparsely stained fast moving bands (RF = 0.28 and 0.31) of indigenous B. tabaci. Based on the above results, a simple inexpensive and quick assay method for rapid detection of B biotype involves spotting of homogenates of individual adult whitefly prepared in 15 ìl of protein extraction buffer on to Whatman filter paper disc followed by incubation in substrate solution (Napthyl acetate and Fast blue RR) for 15–20 minutes. Development of distinctly deep purple colour with the homogenates of B biotype and slight purple colour with indigenous biotype was the salient feature of the technique.
