【作者】 张丽丽；

【导师】 郭予元； 高希武；

【作者基本信息】 中国农业大学 ， 农业昆虫与害虫防治， 2014， 博士

【摘要】 乙基多杀菌素是由土壤放线菌产生的天然产物,对多种重要农业害虫有毒杀作用,新颖特别的作用机理使其成为目前市场上防治害虫的潜力新型杀虫药剂。乙基多杀菌素可以有效的防治棉铃虫等鳞翅目害虫,研究乙基多杀菌素对棉铃虫的胁迫效应和对天敌的影响,可以为棉铃虫的综合防治提供理论依据。主要结论如下：1.乙基多杀菌素和阿维菌素对棉铃虫、小地老虎、斜纹夜蛾和甜菜夜蛾都有致死效应,而且与阿维菌素相比,乙基多杀菌素对这四种鳞翅目害虫的毒力更高；但乙基多杀菌素对绿盲蝽和棉蚜没有致死效应,而阿维菌素对棉蚜有很好的防治效果；测定了乙基多杀菌素和阿维菌素对采自不同地域的田间棉铃虫种群的毒力效果,发现乙基多杀菌素的毒杀效果较好,而且不同地理种群棉铃虫的LC50无显著差异,但阿维菌素对不同地理种群棉铃虫的毒杀效果差异较大；用乙基多杀菌素处理抗Bt棉铃虫种群和敏感种群,结果发现乙基多杀菌素与Bt蛋白之间存在一定的负交互抗性。2.通过田间小区试验,我们研究了乙基多杀菌素对棉田主要害虫和天敌的影响。结果表明,与对照相比,高剂量乙基多杀菌素和阿维菌素对棉蚜、棉盲蝽种群增长有一定的抑制作用；但对烟粉虱没有显著影响；对瓢虫、小花蝽和草蛉和寄生性天敌的田间种群数量也没有显著性影响。3.研究乙基多杀菌素亚致死剂量对棉铃虫生长发育的影响。结果发现,乙基多杀菌素处理后,棉铃虫幼虫的存活率随着药剂的剂量增加而降低；同时不同剂量乙基多杀菌素可以降低棉铃虫的幼虫体重、蛹重、化蛹率和羽化率；幼虫历期、预蛹期和蛹期延长,同时棉铃虫成虫的单雌产卵量、卵孵化率也降低。4.不同剂量乙基多杀菌素处理后,棉铃虫体内解毒代谢酶发生变化,棉铃虫体内的羧酸酯酶、谷胱甘肽-S-转移酶活力降低,且随着处理的乙基多杀菌素浓度升高而下降,但乙基多杀菌素处理后,棉铃虫体内的乙酰胆碱酯酶、多功能氧化酶比活力增加,并且随着乙基多杀菌素浓度增加而增大。5.通过转录组测序比较分析了乙基多杀菌素处理组与对照组棉铃虫之间的基因表达在转录组水平上的差异,并通过定量PCR的方法验证了部分差异基因在棉铃虫体内的表达量差异。通过转录组测序结合生物信息学分析发现乙基多杀菌素处理后,一些基因表现为上调和下调。其中包括与作用靶标、神经调控蛋白、表皮蛋白、解毒代谢、修复免疫和能量代谢等相关的基因。更多还原

【Abstract】 Spinetoram is a kind of natural substance produced by soil actinomycete, which is toxic to many major agricultural insect pests. At present, spinetoram becomes a potential insecticide to control insect pests in the market because of its novel special action mechanism. Spinetoram is effective to some lepidoptera species, such as cotton bollworm, Helicoverpa armigera (Hubner), and research on the action mechanism of spinetoram on H. armigera could provide a theoretical basis for rational use of spinetoram. The main results are as follow:1. Both spinetoram and abamectin had lethal effect to some lepidoptera species such as H. armigera, Spodoptera exigura, Spodoptera litura and Agrotis ipsilon. Compared with abamectin, spinetoram had better control efficiency to these four lepidoptera species, but spinetoram had no activity on Apolygus lucorum and Aphis gossypii, while abamectin could control A. gossypii well. The toxic efficiency of spinetoram and abamectin to H. armigera which collected from different geographical locations were determinated. Spinetoram had better efficiency than abamectin, and the differences of LC50S of spinetoram among H. armigera populations from different locations were not significant, but differences of the LC50S of abamectin among different location populations were obvious. After treated Bt-resistant and Bt-susceptible H. armigera strain with spinetoram, the results showed a little negative cross-resistance between spinetoram and Bt.2. The impact of spinetoram on major insect pests and natural enemies in cotton field were evaluated by field plot experiments. Compared with control, high-dose of spinetoram and abamectin could inhibit the population increase of cotton aphid and cotton mirid bug, but had no obviously effect on whitefly population. Spinetoram had no obviously effect on parasitoids and predators such as ladybug, orius, and lacewing.3. The effects of sub-lethal dose of spinetoram on growth and development of H. armigera were analyzed. After treated by spinetoram, the survival percentage of H. armigera larvea reduced along with increasing of the treated dose. The larval weight, pupal weight, pupation rate and eclosion rate reduced after treated by spinetoram at different doses. The larval development time, pre-pupal duration and pupal duration delayed, the eggs laid per female and egg hatch percentage were also reduced after treated with spinetoram.4. The enzyme activities of H. armigera larvae were changed after treated withdifferent dose of spinetoram. The activities of CarE (carboxylesterase) and GST (glutathione-S-transferases) were reduced along with increasing of the treated doses. However, the activities of AchE (acetylcholinesterase) and MFO (mixed-function oxidases) were promoted along with increasing of the treated doses.5. The gene changes of H. armigera larvae aftertreated with spinetoram were analyzed at transcriptional level using transcriptome sequencing analysis method, and expressions of parts of changed genes were verified by qRT-PCR. By transcriptome and bio-information analysis, we found some genes expressed higher and some expressed lower in treated H. armigera larvae than control. The unigenes maybe involved in the action process of spinetoram on H. armigera, and the functions of these unigenes were annotated as action target, cutieular protein, detoxification and metabolism, repair and immune, and regulation.更多还原