烟粉虱对吡虫啉的室内抗性发展动态及其生化机制

摘要

The imidacloprid-resistant Bemisia tabaci ( Gennadius) populations were screened for continuous 14 generations in laboratory by using dipping method. The results showed that:the resistance of B. tabaci to imidacloprid increased slowly in the earlier period of screening ( 1～6 generations); but it increased quickly from the 8th generation, and the resistance ratio reached 8.64-fold in the 14th generation;from the first generation to the 14th generation, the slope values in the toxicity regression equa-tions of resistant populations decreased from 1.772 to 0.838. In addition, the activities of Carboxylesterase (CarE), GSH-S-transferase ( GSTs) and Multifunctional oxidase ( MFO) in sensitive population and resistant population of B. tabaci were deter-mined, and the results indicated that the activity of CarE and MFO in the resistant population was separately 2.35 times and 1.20 times that in the sensitive population, suggesting the increase in CarE and MFO activity was the main reason for the increase in imidacloprid-resistance of B. tabaci; while there was no significant difference in GSTs activity between these two populations.%通过室内吡虫啉汰选法,对烟粉虱种群进行了连续14代的抗性筛选.结果显示:在筛选初期(1～6代),吡虫啉抗性增长较为缓慢,从第8代起抗性增长速度加快,到第14代时抗性达到8.64倍,且毒力回归方程中的斜率由1.772降低为0.838.此外测定了烟粉虱敏感种群和抗性种群羧酸酯酶(CarE)、谷胱甘肽-S-转移酶(GSTs)和多功能氧化酶(MFO)的活性,结果显示:抗性种群的CarE和MFO活性分别是敏感种群的2.35和1.20倍,表明CarE和MFO活性增强是烟粉虱对吡虫啉抗性增加的重要原因;而两个种群间GSTs活性差异不显著.