二斑叶螨对甲氰菊酯的抗性选育及解毒酶活力变化

Resistance selection with fenpropathrin and the change of detoxification enzyme activities in Tetranychus urticae Koch (Acari:Tetranychidae)

为了明确二斑叶螨Tetranychus urticae Koch对甲氰菊酯产生抗性的机理,在室内模拟田间药剂的选择压力,用甲氰菊酯对二斑叶螨敏感品系(S)进行逐代汰选,选育至38代时,获得了抗性倍数(resistance ratio,RR)为247.35的抗甲氰菊酯品系(Fe-R)。对S和Fe-R解毒酶活性的分析表明,Fe-R_(38)体内羧酸酯酶(carboxylesterase,CarE)、酸性磷酸酯酶(acid phosphatase,ACP)、碱性磷酸酯酶(alkaline phosphatase,ALP)、谷胱甘肽-S-转移酶(glutathione stransferase,GSTs)和多功能氧化酶(mixed function oxidase,MF0)较S体内相应酶的活力显著升高(p<0.05),其相对比值(R/S)分别为1.822,13.941,3.789,4.262和17.386。此外,筛选至第9,19,25,32代时,除Fe-R_(25)和Fe-R_(32)的MFO活性与S相比有显著性差异(P<0.05)外,其余解毒酶(CarE,ACP,ALP,GSTs)的活性与S相比均无显著性差异(P>0.05)。筛选至第38代时,5种解毒酶的活力与S相比均差异显著(P<0.05)。结果说明二斑叶螨Fe-R随着筛选代数的增加(第25代后),MFO活性的上升可能是二斑叶螨对甲氰菊酯产生抗性的主要原因。

In order to clarify the mechanisms of deltamethrin resistance in Tetranchus urticae Koch. Pyrethroid acaricide fenpropathrin was used to select the resistance in T.urticae in the laboratory.Selected with fenpropathrin for 38 generations,T.urticae developed 247.35-fold resistance to fenpropathrin.The activities of detoxification enzymes were measured and compared between the susceptible strain（S） and the fenpropathrin-resistant strain（Fe-R） of T.urticae.The results showed that the activities of carboxylesterase （CarE）,acid phosphatase（ACP）,alkaline phosphatase（ALP）,glutathione S-transferases（GSTs） and mixed function oxidase（MFO） in Fe-R_（38） were significantly higher than those in S strain,increased by 1.822-,13.941-,3.789-,4.262- and 17.386-fold,respectively.However,except that the activity of MFOs in Fe-R_（25） and Fe-R_（32） showed significant difference from that in S strain（P〈0.05）,the activities of other detoxification enzymes（CarE,ACP,ALP,GSTs） in the resistant strain selected for 9,19,25,and 32 generations were significantly different with those in S strain.The activities of all the detoxification enzymes in the resistant strain selected for 38 generations were significantly different with those in S strain （P〈0.05 ）.These results suggest that with the increasing of selection generations（after the 25th generation） with fenpropathrin,the increased activity of MFO may the main factors responsible for the resistance of T.urticae to fenpropathrin.