黄花蒿精油对玉米象成虫体内酶活力的影响

用5种体积分数的黄花蒿精油处理玉米象成虫,测定了处理后不同时间其体内几种酶活力的变化情况。与对照组相比,所有处理组的乙酰胆碱酯酶(AChE)活力在处理后2h内均大幅下降,且随着处理体积分数的增大活力降低;处理4h后,5%～20%处理组的活力有所恢复。α-乙酸萘酯酶(α-NACarE)活力在处理后2～12h内呈下降趋势,处理后24h活力逐渐恢复。谷胱甘肽-S-转移酶(GSTs)活力在处理后2h时降低,处理后4h活力有所恢复。过氧化物酶(POD)活力在2h内均大幅下降;处理4h后,5%～20%处理组的POD活力有所恢复,1%处理组在处理后8h活力显著高于对照组。试验结果表明,在试虫接触药剂的初期解毒酶活性受到抑制,而后由于机体的抵抗作用,解毒酶活力有所恢复,反映出玉米象成虫对黄花蒿精油存在解毒机制。但是随着精油体积分数的增大,黄花蒿精油较强的毒害作用抑制了解毒酶的活性,解毒酶活力反而下降。

Effect of Essential Oil Extracted from Artemisia annua L.on Activities of Several Enzymes in Sitophihus zeamais

The activities of acetylcholinesterase (AChE), carboxylesterase (α-NACarE), glutathione S transferase (GSTs) and peroxidase (POD) of Sitophihus zeamais contacted with a series　of  concentration of essential oil (1％, 5％, 10％, 15％, 20％) extracted from Artemisia annua L. were measured at2, 4, 8, 12, 24 h. Compared with the control group, the AChE activities of all treatment groups significantly decreased at 2 h. When reaching 4 h, the activities of 5％ treatment group to 20％ treatment group were recovered. The α NACarE activities of all treatment groups decreased within 2, 4, 8, 12 h until the activities gradually recovered at 24 h. The GSTs activities of all treatment groups reduced at 2 h and resumed after 4 h. The POD activities of all treatment groups significantly decreased at 2 h, the activities of 5％ treatment group to 20％ treatment group were in the recovery after 4 h, after 8 h, the activity of 1％ treatment group was significantly higher than the control group. The results showed that in the early stage when contacting with the essential oil of A. annua, the detoxification enzyme activities of S. zeamais were inhibited. Along withtheresistance of the body, detoxification enzyme activities restored. It reflectedthat the S. zeamais had detoxification mechanism on the essential oil of A. annua, but with the increase of concentration of essential oil, the activities ofdetoxification enzymes became worse. This study helps to understand the insecticidemechanisms of essential oil.