抗马拉硫磷褐飞虱品系的交互抗性及其生化分析

用马拉硫磷筛选的褐飞虱抗性品系(R)对马拉硫磷的抗性达到184．4倍，对作用于乙酰胆碱酯酶的二嗪磷、异丙威和仲丁威有一定的交互抗性，而对氰戊菊酯不表现显的交互抗性。进一步研究显示：在抗性品系中，磷酸三苯酯对马拉硫磷和仲丁威的增效作用分别达到9．15和2．38倍，顺丁烯二酸二乙酯对这两个药剂也有一定的增效作用(2．32和1．42倍)。抗性品系的酯酶、谷胱甘肽-S-转移酶(以2，4二硝基氯苯为底物)和多功能氧化酶活力分别为敏感品系(S)的14．67、1．52和1．11倍。在抗性品系中，磷酸三苯酯对酯酶活力抑制作用很强，顺丁烯二酸二乙酯对谷胱甘肽-S-转移酶活力也存在一定的抑制作用。实验结果显示，酯酶和谷胱甘肽-S-转移酶在抗性品系对马拉硫磷抗性和对其他药剂的交互抗性中起到不同程度的重要作用。

Cross resistance of malathion resistant strain of Nilaparvata lugens and its biochemical aspects

The resistant strain(R)of brown planthopper selected by malathion held 184 4 fold resistance to malathion and showed obvious cross resistance to all the acetylcholine receptor targeting insecticides tested,but not to fenvalerate.Further study demonstrated that TPP had significant synergism on malathion(SR:9 15)and some on fenobucarb(SR:2 38),and DEM had some synergism to malathion(SR:2 32)and to fenobucarb(SR:1 42)in R strain.Biochemical assay showed that R strain had esterase activity 14 67 times that in susceptible strain(S),GST with CDNB 1 52 and MFO only 1 11.And TPP could significantly inhibit the esterase activity in R strain,and DEM also could inhibit the GST activity to some extent in R strain.It is concluded that the esterase and GST played an important role in the malathion resistance and the cross resistance to fenobucarb to different extents.