SCAR markers for identification of host plant specificity in whitefly, Bemisia tabaci (Genn )

摘要

RAPD markers (8 in number) which identified specificity in Bemisia tabaci (Genn ) to a single or two different host plants (out of cotton brinjal tomato soybean and Sida sp a weed) were sequenced Based upon these nucleotide sequences 8 sets of SCAR primers were developed for PCR amplification of the respective SCAR markers from B tabaci genotype holding specificity to a specific host plant During evaluation these primers amplified SCAR markers of expected sizes as per position of primer sequences in the determined sequence for the respective RAPD marker and only from the specific B tabaci genotype Subsequent validation of each of these SCAR markers with 10 individuals from a freshly collected B tabaci population from the respective field of above field crops (and potato) and wildly growing Sida sp plants resulted in correct amplifications with majority of the whitefly individuals (6-8) while the specific SCAR marker was not amplified with a small fraction of B tabaci individuals (2 4) Thus the SCAR markers were found to be true to their identity, whereas failure to amplify the same from minor fraction of the field population could be due to mixed population effect wherein the field population gets mixed with whitefly from alternate source crops and remained undetected The finding that majority of the individuals being detected by respective marker supported the specificity of developed SCAR markers for molecular monitoring of host specific B tabaci individuals and populations besides establishing the existence of host selection of whitefly by the plant host type in nature