Department of Plant Pathology, University of Agricultural Sciences, GKVK, Bangalore-560065.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
The whitefly Bemisia tabaci B biotype is a potent vector of geminiviruses of agriculture and horticultural crops. At present determination of biotypes of B tabaci whitefly has been on the basis of variation in protein or DNA. Quick and in expensive tests were developed to detect the B biotype in the whitefly populations based on Carboxyl esterase activity. The methods involved the testing of the homogenates from single or a group of 5 or 10 adult whiteflies taken in a test tube or blotted on a blotting paper and incubating with Napthyl acetate for 20 minutes followed by addition of Diazo Blue Laurate solution (5% SDS+ 1% Diazo blue salt in 5:2) to develop colour and termination of the reaction. By comparing the staining of B biotype and non B biotype populations for esterase activity, the B biotype could be distinguished. The B biotype produced deep blue colour, where as indigenous non B biotype produced light blue colour. The techniques worked well for testing of field populations of whitefly B. tabaci. The methods are simple, sensitive, require in expensive materials and produce a permanent record of results.
