【作者】 姚洪渭；

【导师】 程家安；

【作者基本信息】 浙江大学 ， 农业昆虫与害虫防治， 2001， 博士

【摘要】 本论文就白背飞虱Sogatella furcifera（Horvath）药剂敏感性变化的种群生物学与生理生化基础作了研究。结果如下。1 不同地区种群药剂敏感性及其相关酶系活性与频率分布的比较 就白背飞虱浙江和广西种群（迁入虫源）、云南和海南种群（当地虫源）对马拉硫磷、甲胺磷、叶蝉散和扑虱灵敏感程度，以及与抗性相关酶系即酯酶、羧酸酯酶、谷胱甘肽-S-转移酶和乙酰胆碱酯酶等比活力的测定结果表明，各种群对马拉硫磷、叶蝉散均已产生明显抗性，抗性倍数各为16.20～137.24和10.25～15.58。种群间相比，云南和海南种群对各药剂抗性水平及雌成虫酶活性均明显较高，但个体异质性则低于浙江和广西种群。各种群成虫酯酶同工酶谱基本相同，均可见6条谱带，迁移率各为0.012、0.05、0.08、0.11、0.14和0.18。谱带染色深度与酶活测定结果一致。各种群所有指标的地区差异暗示了长距离迁飞对飞虱抗药性水平的选择作用。2 药剂敏感性及其抗性相关酶系活性与水稻品种的关系 白背飞虱若虫在中抗品种N22上饲养所得雌成虫对马拉硫磷敏感性明显较高；对叶蝉散敏感性正相反。这可能分别与飞虱体内羧酸酯酶活力下降和谷胱甘肽-S-转移酶等活力上升有关。成虫取食N22后，对马拉硫磷敏感性随取食天数增加呈增高趋势；羧酸酯酶在取食1天后即表现高水平的诱导活性，后随取食时间延长而降低。对叶蝉散的敏感性随取食N22天数增加而降低，可能与乙酰胆碱酯酶低水平活性有关。白背飞虱取食抗褐飞虱品种ASD7后，其体内酶活及对药剂抗性多有升高趋势。不同水稻品种中总酚含量以N22显著为高，相关分析表明，水稻叶鞘中的酚类物质可能是品种影响飞虱药剂敏感性的主要因素之一。因此，在生产实践中，适宜的杀虫剂与飞虱抗性品种应协同使用，以充分发挥各自的有效作用。3 药剂敏感性及其相关酶系活性与频率分布的世代变化 白背飞虱在室内连续饲养53代后，对甲胺磷敏感性基本保持不变，表现较强的稳定性。对马拉硫磷和叶蝉散抗性出现一定程度衰退，其中马拉硫磷抗性由原未40.4倍下降至9.6倍；叶蝉散抗性由11.1倍下降至3.1倍。对飞虱体内抗性相关酶（酯酶、羧酸酯酶、谷胱甘肽-S-转移酶和乙酰胆碱酯酶）活性及其频率分布的代别变化分析表明，马拉硫磷抗性衰退与羧酸酯酶活性降低呈显著正相关。4 药剂敏感性相关酶系活性的发育时间特征及化学杀虫剂对其的影响 白背飞虱从初孵若虫发育到5龄，体内酯酶、羧酸酯酶和谷胱甘肽-S-转移酶活性均逐渐增大，而乙酰胆碱酯酶活性逐渐减小，这表明飞虱随发育龄期增长，对多种杀虫剂的抗性表现逐渐增强。白背飞虱雌成虫抗性相关酶系比活力随日龄增长呈下降趋势，而雄虫酶活性的日龄变化呈波动现象。低剂量浓度（LD₅）药剂处理后，白背飞虱抗性相关酶活性受不同程度抑制，表明药剂对飞虱体内微环境的影响颇为显著。药剂处理后，成虫酯酶活性显著低于若虫，后随时间延长呈上升趋势，而若虫则正相反，表明白背飞虱成虫的恢复能力较强。5 不同品系抗药性相关酶系特性的比较 对白背飞虱敏感品系、抗马拉硫磷品系和耐叶蝉散品系体内抗性相关酶活性及其动力学常数测定表明，抗马拉硫磷品系羧酸酯酶比活力、V_max与K_m分别是敏感品系的2.0倍、3.2倍和4.3倍，均达显著水平，表明飞虱对马拉硫磷抗性是由于羧酸酯酶性质发生改变，酶量及活性增加引起。酯酶同工酶等电聚焦电泳证实，与…二6－5．84酯酶扩增有关。酶动力学试验与酶抑制试验结果表明，乙酚胆碱酯酶敏感度降低是导致白背飞虱对叶蝉散的耐性增加的主要机制。6 搜团配酶与乙醚胆碱团日的体扈分布 白背飞虱若虫头、胸、腹部中CaE活性分别占50．8％、26刀％和23．2％，雌成虫各占33．0％、23．5％和43．5％，雄成虫各占26．5％、23．2％和50．3％。若虫、雌雄成虫的A。hE活性均主要分布于头部，各占总活性的 87．7％、71＊％和 74．7％。差速离心结果表明，该飞虱 Call主要位于胞质溶胶层中，其活性占 57．G66．9％；AChE活性在胞质溶胶层中仅占 5．8一门．0％，而62．8－76．9％的活性则分布于线粒体层、细胞核和细胞碎片层中。在细胞中，CaE可能主要以可溶性蛋白大分于形式存在：MM则以膜结合态和可溶性态双重形式存在。7不同品系杂交后药剂域感性及其相关酶系活性的比较 白背飞虱对马拉硫磷的抗性可能为常染色上单因于的不完全显性遗传，对马拉硫磷的抗性现实遗传力 hZ为 0．059。白背飞虱抗性相关酶的活性多受性连锁效应与直接加性效应控制，可溶性蛋白含量主要受性连锁效应与直接显性效应控制，表明抗性相关酶系在飞虱上下代遗传中可被固定，而可溶性蛋白虽能遗传但不能被固定，随基因在不同世代中的分离和重组而发生改变。抗性相关酶活性与可溶性蛋白含量的遗传均存在显著的性连锁，表明两者在飞虱不同性别中的遗传表现均不相同，这与飞虱雌性成虫酶活性及蛋白含量明显高干雄性成虫相一致。抗性相关酶活性成对性状的遗传协方差分析表明，以解毒代更多还原

【Abstract】 In this paper, biological, physiological and biochemical bases for changes in insecticide susceptibility of the white-backed planthopper (WBPH), Sogatella furcifera Horvath are studied. The results are shown as follows.1 Comparison of insecticide susceptibility, activities of resistance-related enzymes and their frequency distributions among different populationsThe susceptibility of 4 WBPH populations collected in Zhejiang, Guangxi, Yunnan and Hainan provinces, China, respectively, to 4 insecticides (malathion, methamidophos, isoprocarb and buprofezin) and the activity of 4 enzymes (esterase, carboxylesterase, glutathione S-transferase and acetylcholinesterase) related to resistance were determined. Compared to results of a similar study by Fukuda et al. in 1969, there were significant increases in LDso values: 16.2-137.2 times higher for malathion and 10.3-15.6 times higher for isopcocarb. Both populations from Yunnan and Hainan were less susceptible but more heterogeneous to insecticides than those from Zhejiang and Guangxi, and this was reflected in higher enzyme activities in female adults. The zymogram for esterase isozymes was similar among different populations, with 6 bands, of which Rf values were 0.012, 0.05, 0.08, 0.11, 0.14 and 0.18, respectively. The staining level of zymogram in populations was corresponding with the activities of esterase tested. According to geographical difference in all evaluated indexes among populations, it could be inferred that long-distance migration may perform as a selection factor on resistance level of WBPH.2 Impacts of rice varieties on insecticide susceptibility and activities of resistance-related enzymes of WBPHThe female adult developed from WBPH nymph fed on N22, a middle-resistant variety, was more susceptible to malathion, and inversely to isoprocarb, while the activity of carboxylesterase was obviously suppressed but the others enzymes such glutathione S-transferase, alkaline phosphatase and acid phosphatase with the increase activities. The susceptibility of WBPH adults to malathion increased as the period fed on N22 increased. The activity of carboxylesterase was induced highly after fed on N22 for one day, then it declined successively. The day changes of the susceptibility to isoprocarb showed an adverse tendency against it to malathion, which maybe due to the decrease of the activity of acetylcholinesterase correspondingly. The adult resistance level to insecticides and enzyme activities seemed to be heightened after feeding on ASD7, a variety143resistant to BPH. The total phenol content in rice leaf sheath was the highest in N22, and could be regarded as one of the factors, which caused changes in susceptibility of WBPH to insecticide after feeding different rice varieties. It was recommended that suitable insecticides and planthopper resistant varieties should be coordinately used in practice so that they contribute more effects respectively.3 Changes in insecticide susceptibility, activities of resistance-related enzymes and their frequency distributions among the generationsThe susceptibility to methamidophos of WBPH showed no change after 53 generations successively rearing in the laboratory without use of insecticide. The resistances to malathion and isoprocarb were unstable, which decreased from 40.4-fold to 9.6-fold and from 11.1-fold to 3.1-fold, respectively. The analysis of changes in the activities and their frequency distributions of resistance-related enzymes, i.e. esterase, carboxylesterase, glutathione S-transferase and acetylcholinesterase, among the generations indicated that the reversion of malathion resistance was positively related to decrease in the activity of carboxylesterase significantly.4 Impacts of developmental stages on the resistance-related enzyme activities and the effects of insecticides on themActivities of esterase, carboxylesterase and glutathione S-transferase gradually increased with the growth of WBPH nymph from lsl instar to 5n instar, conversely that of acetylcholinesterase decrease更多还原