【作者】 张芳；

【导师】 高宝嘉；

【作者基本信息】 河北农业大学 ， 森林保护， 2004， 硕士

【摘要】 转双抗虫基因741杨对节肢动物群落的影响是转基因杨安全性评价的重要内容。本文运用群落生态学、种群生态学的理论和方法，以转双抗虫基因(BtCrylAc和API)741杨中抗PB17、PB1，高抗PB11、PB29为试验材料，以普通741毛白杨为对照，对转基因741杨节肢动物群落的结构与功能、多样性指数、主要害虫的发生发展动态等展开了研究，并在群落研究的基础上从天敌和寄主间相互作用及害虫种群数量动态的变化方面探讨了抗虫基因对节肢动物影响的机制，旨在为转基因741杨安全性评价积累科学数据，为科学评价抗虫基因植物对节肢动物群落影响机制作以探讨。 1 用随机抽样的方法，研究了转基因741杨对节肢动物群落的结构影响。试验设置对照与中抗PB1、PB17和高抗PB11、PB29五个处理。结果表明，转基因杨生境中节肢动物群落与对照相比：各功能团优势类群组成基本相同，害虫亚群落中靶标害虫的数量明显降低，寄生性天敌优势种的优势度下降，捕食性天敌的种类和数量没有明显变化。转基因741杨节肢动物群落的多样性、均匀度、优势集中性的结果表明转基因杨节肢动物的群落多样性和均匀度高于对照杨林；害虫亚群落的优势集中性低于对照；主要害虫不易大发生；转基因杨对天敌亚群落的影响程度不大。 2 通过对转基因抗虫杨林中主要害虫和天敌的种群动态研究表明，转基因杨对林中主要靶标害虫舞毒蛾、杨白潜蛾有很好的控制作用，对非靶标害虫无明显作用，但并未出现次要害虫大发生的情况。主要捕食性天敌的数量与对照相比无明显的变化，说明转基因741杨对主要捕食性天敌影响不明显；而各系号转基因杨林中寄生性天敌粘虫白星姬蜂的数量明显减少，说明转基因741杨对节肢动物群落中寄生性天敌种群影响较大。 3 通过对舞毒蛾、杨扇舟蛾两种靶标害虫在转基因741杨林和对照林中田间自然种群生命表的比较研究得出，田间转基因系号林分中舞毒蛾、杨扇舟蛾的世代存活率与对照相比显著降低，种群趋势指数下降了5.65～19.26倍，由原来的高于1降到低于1，即转基因杨可以减少靶标害虫的自然种群数量，降低害虫大发生的几率能起到有效的作用。经存活曲线分析得知舞毒蛾、杨扇舟蛾的自然种群的个体死亡主要发生在小幼虫期，抗虫系号对一、二龄小幼虫的致死能力更为明显。经过对转基因和对照林中舞毒蛾、杨扇舟蛾自然种群死亡因子致死力比较分析可知：转基因杨林中舞毒蛾和杨扇舟蛾自然种群的各个龄期的死亡率均高于对照，其中，由毒蛋白直接引起的食物和环境共同作用、病菌致死以及间接引起的化蛹死亡率升高的最为明显。 4 通过对三交花蛛、七星瓢虫两种捕食性天敌对转基因杨处理过的舞毒蛾的捕食试验表明，三突花蛛、七星瓢虫对转基因杨处理过的舞毒蛾的捕食曲线符合Holling Ⅱ型曲线，其捕食缝、处理时间、瞬时攻击率略有增加，可以说明抗虫基因不能通过食物链的营养流经靶标害虫进入捕食性天敌体内;或是可以进入天敌体内，但天敌体内缺少与毒蛋白结合的受体，所以毒蛋白不能对捕食性天敌造成直接的影响。更多还原

【Abstract】 Effects and mechanisms of transgenic BtCry1Ac plus API 741 poplar on insect communities were studied by field plots investigating from the view of bionomics, population ecology, and community ecology. The experimental 741 poplar varieties were high insect-resistance hybrid poplar 741 (PB11, PB29), and medium insect-resistance hybrid poplar 741(PB17, PB1). The purpose of this study is to accumulating scientific basis for the evaluation of bio-safety of transgenic 741 poplar, utilizing the transgenic poplar reasonably. The results are as follows:1. The dominant group compositions of arthropod guilds were almost the same between transgenic 741 poplar and their control. The diversity and evenness of arthropod communities in transgenic 741 poplar were higher than the control. Density of the target pest population was significant descended, and the dominant concentration of the pest sub-community was lower significantly in contrast of the control. The dominance distribution of parasitoid enemies in transgenic 741 poplar were decended in contrast of control, the number and speciecs of the predator enemies were not significant different from those of control. So the arthropod community of transgenic 741 poplar were stable, they had better buffering action to the changing from population inside or the changing outside.2. Transgenic 741 poplar show magnificent control on dominant target pest (Lymantria dispar and Clostera anachoreta ), but the affects on non-target pests were not clear. The difference between number of dominant predator enemies in transgenic 741 poplar and its control were not significant. The population density of one dominant predator was decreased clearly in contrast of the control, that showed a obvious affection over predator enemy populations.3. Six life tables of Lymantria dispar and Clostera anachoreta were established which were fed with 2 kinds of transgenic 741 poplar and the control. The result showed that the indexes of population trend of the pest in transgenic poplar were 5.65-19.26 times lower than the control, that’s means transgenic 741 poplar can reduce the density of target insect population. The highest mortality occurred at the boring stage of young instars larvae, and in transgenic poplar the mortality rate of every instars larvae were more than 90 per cent, obviously higher than the control, the most clear death factor among all were: food and environment co-affect factor, diseases and the pupa natural death caused by the transgenicpoplar.4. Predation amounts and functional responses by Cocinellas septempunctata and Misumenops tricuspidatus on Lymantria dispar which were fed with transgenic 741 poplar with BtCry1Ac and API gene, were evaluated under laboratory conditions. Both on these two preys, functional responses by the spider followed the Holling "disc equation" for type II response. When the larvae of the Lymantria dispar fed with leaves of transgenic poplar were as prey, the killed amount by the predator and the attack constant were increased and handing time were shorter than those of control. But those difference were not reach the significant level. To consider the tested results, it may be drawn that there no marked negative effect of transgenic 741 poplar on predation by Cocinellas septempunctata and Misumenops tricuspidatus.更多还原