【摘要】 通过增效剂生物测定和生化分析,探讨了采自福建省的B型烟粉虱Bemisia tabaci6个田间种群对毒死蜱和敌敌畏抗性的生化机制。结果表明:与敏感品系SUD-S相比,6个田间种群对毒死蜱和敌敌畏分别具有54.53~78.43倍和6.23~11.25倍的抗性。TPP、PBO和DEM对毒死蜱的增效比分别为3.61~24.94倍、1.14~1.76倍和1.04倍,对敌敌畏的增效比分别为1.67~2.64倍、1.33~1.65倍和1.09倍,表明羧酸酯酶的解毒代谢在烟粉虱对毒死蜱的抗性中起着重要作用。烟粉虱抗性种群乙酰胆碱酯酶的Km值是敏感品系的1.83~4.0倍,Vmax值是敏感品系的0.34~0.62倍;敏感品系乙酰胆碱酯酶的活性在底物浓度大于1.0mmol/L时受抑制,抗性种群乙酰胆碱酯酶的活性在底物浓度大于16mmol/L时受抑制;抗性种群乙酰胆碱酯酶对敌敌畏和毒死蜱的敏感度分别比敏感品系低119.92~161.33倍和10.11~14.24倍,表明烟粉虱田间抗性种群乙酰胆碱酯酶可能已发生了变构,由变构引起的乙酰胆碱酯酶不敏感是烟粉虱田间种群对毒死蜱和敌敌畏产生抗性的重要原因。结果提示,乙酰胆碱酯酶不敏感性和羧酸酯酶的解毒代谢在烟粉虱对毒死蜱的抗性中均起着重要作用,而乙酰胆碱酯酶不敏感性在对敌敌畏的抗性中起重要的作用,多功能氧化酶和谷胱甘肽S转移酶在烟粉虱对毒死蜱和敌敌畏抗性中所起的作用不大。更多还原

【Abstract】 Biochemical mechanisms of resistance to chlorpyrifos and dichlorvos were investigated in six field populations of Bemisia tabaci collected from Fujian Province of China with synergist bioassay and biochemical analysis. Compared with the susceptible SUD-S strain, the six field populations showed 54.53-78.43 and 6.23-11.25-fold resistance to chlorpyrifos and dichlorvos, respectively. TPP, PBO and DEF had 3.61-24.94, 1.14-1.76, and 1.04-fold synergistic effect on chlorpyrifos, and 1.67-2.64, 1.33-1.65 and 1.09-fold synergistic effect on dichlorvos, respectively, suggesting that carboxylesterase (CarE)-based detoxification could be an important resistance mechanism to chlorpyrifos in B. tabaci. K_m and V_ max of acetylcholinesterase (AChE) of the six field resistant populations were 1.83-4.0 and 0.34-0.62 times those of the SUD-S strain. Activity of AChE was inhibited both in the SUD-S strain and the resistant field populations when their subtrate concentrations were higher than 1.0 mmol/L and 16.0 mmol/L, respectively. AChE of the six field resistant populations was 119.92-161.33 and 10.11-14.24-fold less sensitive to chlorpyrifos and dichlorvos than that of the SUS-S strain, respectively. The results suggest that both insensitive AChE and increased CarE are the major mechanisms conferring chlorpyrifos resistance in B. tabaci, and only insensitive AChE is important for dichlorvos resistance.更多还原