【作者】 帅霞；

【导师】 王进军；

【作者基本信息】 西南农业大学 ， 农药学， 2005， 硕士

【摘要】 本研究以桃蚜为对象,在室内对其进行高效氯氰菊酯和吡虫啉的抗性选育。在抗性选育过程中分别用生物测定法监测LD₅₀值和用微量滴度酶标板法监测酯酶含量与活性的动态变化,以了解抗性发展动态及抗性基因频率的分布情况;并对产生抗性的品系进行抗药性生理生化机制研究。旨在为两种药剂的复配使用提供理论依据并丰富桃蚜的抗药性研究体系。经过近两年的研究,获得了以下主要研究结果: 1.桃蚜对高效氯氰菊酯抗性选育及酯酶含量与活性动态变化 室内对桃蚜进行高效氯氰菊酯抗性选育,抗性筛选3代（F₃）后抗性指数就达13倍,说明桃蚜对高效氯氰菊酯产生了明显的抗性。随着选育代数增加,抗性指数逐渐增强。到第10代(F₁₀),抗性指数达49.86倍。抗性筛选过程中LD-p回归方程的斜率有变小的趋势,表明桃蚜群体中抗性个体不稳定,群体发生了异质性变化,抗性指数有进一步增加的潜力。随着抗性选育代数增加,桃蚜酯酶酶源蛋白含量和酯酶活性逐渐上升,更多的桃蚜个体向酯酶酶源蛋白含量和酯酶活性高的区域分布。到第10代(F₁₀),酯酶含量和活性分别是敏感品系（F₀）的1.85和5.08倍。经相关分析,抗性发展水平与酯酶酶源蛋白含量和酯酶活性显著相关（R=0.933和0.931）,由此可见酯酶在桃蚜对高效氯氰菊酯的抗性发展中可能起着十分重要的作用。 2.桃蚜高效氯氰菊酯抗药性机理研究 2.1 桃蚜高效氯氰菊酯抗药性与酯酶的关系 采用酶标仪技术对桃蚜高效氯氰菊酯敏感和抗性品系体内的酯酶活性进行测定。结果表明桃蚜高效氯氰菊酯抗性品系的酯酶比活力增高,是敏感品系的2.555倍;K_m值和V_max都大于敏感品系,分别为敏感品系的1.520和2.587倍。酯酶同工酶电泳分析显示,桃蚜高效氯氰更多还原

【Abstract】 The resistance of alphamethrin and imidacloprid in Myzus persicae (green peach aphid) was selected in laboratory. In order to learn about the resistance developing dynamic and gene frequency, the resistance development was monitored through the bioassay and the 96-well microplate reader for measuring change of esterase (Est). The resistance mechanisms of Myzus persicae to alphamethrin were studied after 10 times selection to enrich the research contents of Myzus persicae resistance and provide protocol design of resistance management. After two years study, the main research results are summarized as follows.1. The selection of resistance to alphamethrin in Myzus persicae and esterase activity, content dynamicThe results showed that the resistance level gradually rose with the increase of selection time. After three generations, the resistant level of green peach aphids to alphamethrin was 13-fold. While ten generations later, the resistant level amounted to 49.86-fold and the slope (b) value of LD-p lines have decrease tendency. It suggested that the green peach aphids have developed obvious resistance to alphamethrin and resistance would further develop. As resistance developed, enzyme protein content and Est activity increased significantly than susceptible batch and there was a significant correlation between resistance leveal and enzyme protein content, Est activity, respectively. The results showed that the Est might play an important role in the resistance development of green peach aphids to alphamethrin. Comparing the frequency distribution of enzyme protein content and activity, more and more individuals possessed higher content and activity.2. Resistance mechanisms of Myzus persicae to alphamethrin2.1 Est and the resistance of Myzus persicae to alphamethrinThe Est activity of susceptible and resistant green peach aphids were studied using the method of microplate reader, the results showed that the Est activity, Km and Vmax of resistant batch were 2.555-fold, 1.520-fold and 2.587-fold compared with those in susceptible batch, respectively. The esterase isozyme electrophoretic indicated that the resistant batch of Myzus persicae had no E3 esterase band and had higher esterase activity.2.2 GSTs and the resistance of Myzus persicae to alphamethrinThe GSTs activity of resistant batch were 1.734-fold than the susceptible batch. The comparison of Km of GSTs between resistant and susceptible batch showed that the affinity of GSTs of resistant batch to substrate was stronger than susceptible batch. Comparing the frequency distribution of GSTs activity, it was found that more and more individuals possessed higher activity.23 Phosphatase and the resistance of Myzus persicae to alphamethrinBy biochemical assay, the activities of ACP and ALP in resistant batch were significantly higher than those in susceptible batch, respectively. Both Km and V_max of ACP between resistant and susceptible batch have no obvious change. Compared to susceptible batch, K_m of ALP in resistant batch has no obvious change. On the contrary, Vmax was obviously increased. These declared that the increase of phosphatase activity might be an important role in the resistance of green peach aphid against alphamethrin.2.4 MFO and the resistance at Myzus persicae to alphamethrinThe biochemical assay showed that the development of MFO activity in resistant batch was an important reason for the resistance to alphamethrin of Myzus persicae.2.5 AChE and the resistance of Myzus persicae to alphamethrin2.5.1 AChE activity of susceptible and resistant Myzus persicaeThe AChE activity of susceptible and resistant batches were detected by microplate reader in the experiment. The activity and Vm of resistant batch were significant higher than those of the susceptible batch. These results showed that AChE content of resistant green peach aphids increased. Comparing the frequency distribution of aphid AchE activity, we found that more and more individuals possessed higher AChE activity.2.5.2 AChE inhibition of suscepitible and resistant Myzus persicae更多还原