转基因Bt棉挥发性化学物质对害虫及天敌的影响

Plantation of transgenic Bt cotton in large scale might have adverse impacts on ecosystem and environment, so it is very necessary to take all possible means to assess the risks to avoid disastrous consequences. This research, one of the aspects in risk assessment of transgenic Bt cotton, mainly focuses on the influences of exotic insertion on cotton physiology, on changes in components and concentration of volatile chemicals, and on behaviors of insect pests and their natural enemies. Upon planting transgenic Bt cotton, colleting volatile chemicals, bioassays and electrophysiological experiments, we found no difference in volatile components between transgenic Bt cotton and regular cotton. However, differences in concentrations of some components were found. The cotton bollworms laid almost as same amount of eggs on transgenic Bt cotton as on regular cotton. But cotton aphids behaved differently in feeding on transgenic Bt cotton, which needs to be confirmed in a separate project. Behaviors of natural enemies were not influenced on transgenic Bt cotton. From the present experimental data, it can be concluded that insertion of exotic gene into cotton doesn't change components of volatitles, and some differences in concentrations of some components have no significant adverse effects on behaviors of insect pests and natural enemies.

植物挥发性化学物质是植食性昆虫寻找植物和天敌定位寄主的重要刺激源。本项目旨在研究转基因Bt棉挥发性化学物质对棉田害虫及天敌行为的影响。将以常规棉为对照，在棉株不同发育阶段，收集挥发性化学气味，分析其组分和含量；选取重要的害虫和天敌种类，利用行为学和电生理学方法筛选有生物活性的组分；提取或合成具生物活性的物质，利用嗅觉仪或风洞进行定量试验，找出不同物质和浓度组合对害虫和天敌行为的影响，从而分析转基因Bt棉的种植对植物-害虫-天敌三级营养关系的作用及其对棉田生态系统可能造成的影响。