Resistance monitoring and target gene cloning of Bemisia tabaci Q-biotype from Jiangsu Province

Key Words： Bemisia tabaci,resistance monitoring,acetylcholinesterase,sodium channel,target-site associated resistance

Abstract：       The levels of resistance in three field populations of the Bemisia tabaci Q-biotype from Yangzhou,Dongtai and Wuxi in Jiangsu Province to five representative insecticides were determined using the leaf dipping method.The result show that these three populations had low to moderate levels of resistance to cypermethrin and imidacloprid,but remain largely susceptible to abamectin compared to a relatively susceptible population.Two fragments of the B.tabaci acetylcholinesterase enzyme ace1 and para-type voltage gated sodium channel gene,with respective lengths of 287 bp and 184 bp,were amplified by PCR.Sequence analysis suggested the presence of the F331W mutation in acetylcholinesterase ace1 and L925I and T929V mutations in the sodium channel gene,mutations associated with resistance to organophosphate and pyrethroid insecticides,respectively.