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为探讨斜纹夜蛾Spodoptera litura(Fabricius)对氯氟氰菊酯抗性水平与解毒代谢酶之间的关系,以泰安郊区对氯氟氰菊酯抗性为543.7倍的斜纹夜蛾田间种群为材料,研究了药剂汰选与否的抗性动态及不同抗性水平的解毒代谢酶活性变化。结果表明:室内继代饲养至第30代,不接触任何药剂的抗性下降至102.3倍,用氯氟氰菊酯汰选28代后,抗性上升到3049.3倍,而在药剂汰选至第14代,抗性已至2593.8倍时,停止用氯氟氰菊酯汰选,到第30代的抗性又降至786.3倍。表明斜纹夜蛾抗氯氟氰菊酯田间种群,在无药剂选择压力时抗性水平会显著下降,继续给予药剂汰选会使抗性水平显著上升。检测斜纹夜蛾田间种群5龄幼虫中肠酯酶和谷胱甘肽S-转移酶活性,发现与敏感种群有显著性差异,而多功能氧化酶O-脱甲基活性与敏感种群的差异不明显;给予氯氟氰菊酯药剂汰选,酯酶、谷胱甘肽S-转移酶和多功能氧化酶O-脱甲基3种酶的活性均呈显著增加趋势;停止用氯氟氰菊酯汰选后,3种酶的活性又呈显著下降趋势;不接触任何药剂,随着饲养世代数的增加,其酯酶和谷胱甘肽S-转移酶的活性也呈下降趋势。结果提示斜纹夜蛾幼虫酯酶、谷胱甘肽S-转移酶和多功能氧化酶O-脱甲基活性的提高是斜纹夜蛾对氯氟氰菊酯抗性上升的重要原因。
In order to investigate the relationship between cyhalothrin resistance level and detoxification metabolic enzymes in Spodoptera litura (Fabricius), the field population of S. litura in resistance to cyhalothrin in Taian suburbs was used as material , We studied the resistance dynamics of pesticide selection or not, and the changes of detoxifying metabolic enzyme activities at different levels of resistance. The results showed that the resistance in the laboratory to the 30th generation after being fed to the thirtieth generation did not drop to 102.3 folds after being exposed to any drug, and the resistance increased to 3049.3 folds after 28 passages with cyhalothrin. However, 14 generations, the resistance has been 2593.8 times, to stop the selection of cyhalothrin, to the 30th generation of resistance dropped to 786.3 times. The results showed that the resistance of S. litura to cyhalothrin in the field was significantly decreased in the absence of drug selection pressure, and the drug resistance was significantly increased by continued drug selection. The midgut esterase and glutathione S-transferase activities of 5th instar larvae of S. litura were detected and found to be significantly different from those of the susceptible population, while the difference between O-demethylated multifunctional oxidase and susceptible populations was not Significantly; given cyhalothrin drug selection, esterase, glutathione S-transferase and multi-functional oxidase O-demethylation activity of three enzymes were significantly increased; to stop with cyhalothrin After the ester was eliminated, the activity of three kinds of enzymes showed a significant downward trend. The activity of esterase and glutathione S-transferase also showed a downward trend with the increase of feeding generations without exposure to any drug. The results suggest that the increase of esterase, glutathione S-transferase and multi-functional oxidase O-demethylation activity of S. litura larvae is an important reason for the increase of cyhalothrin resistance in S. litura.