基于寄主挥发性物质的圆柏大痣小蜂产卵行为研究

Plant volatile matter plays a key role in oviposition of the insects and is an important information for the exclusive selection of phytophagous insects. The co evolution mechanism perfectly formed between Megastigmus sabinae and Qilian juniper (Sabina przewalskii) cones, but at present oviposition behavior of Megastigmus sabinae and Qilian juniper cone development are still lack basic research, which result in the severe damage trend of Qilian juniper caused by Megastigmus sabinae is difficult to suppress effectively. In this application we will take oviposition behavior and chemical ecological mechanism of Megastigmus sabinae as the starting point, the eclosion, courtship, mating and oviposition behavior characteristics of Megastigmus sabinae will be observed. Using GC-EAD, GC-MS and "Y" type of olfactory compounds analysis and identification technology, chemical compound for biological behavior of Megastigmus sabinae will be identified; volatile chemical signals between insect behavior and host plant will be analysis. By using a single sensor, characteristics of antennal peripheral olfactory nerve of Megastigmus sabinae to feel chemically active material will be conduct for chemical communication mechanism study between Megastigmus sabinae behavior and Qilian juniper cones selection analysis. Results of the research will provide a reliable theoretical basis for coevolution mechanism between Megastigmus sabinae and Qilian juniper and Megastigmus sabinae ecological regulation; and also provide a new and effective way for Megastigmus sabinae population monitoring and chemical control.

植物挥发性物质在昆虫产卵行为中起着关键性作用，是植食性昆虫专一选择的重要信息。圆柏大痣小蜂与祁连圆柏球果之间形成了完美的协同进化机制，但目前有关圆柏大痣小蜂产卵行为与祁连圆柏球果发育之间还缺乏系统性基础研究，导致圆柏大痣小蜂对祁连圆柏造成严重破坏的趋势还难以有效遏制。本项目综合运用生物学、行为学、化学生态学方法，采用动态顶空采集法采集植物挥发性物质，利用GC-MS、GC-EAD、触角电位、风洞和“Y”型嗅觉等化合物分析技术和室内电生理实验、行为实验，进行寄主挥发性物质与圆柏大痣小蜂产卵行为特点研究，明确圆柏大痣小蜂产卵生物学行为的信息传递物质；揭示圆柏大痣小蜂产卵行为与寄主挥发性物质之间的关系，阐明圆柏大痣小蜂产卵与寄主球果选择的化学通讯机制，为圆柏大痣小蜂与寄主的协同进化和圆柏大痣小蜂的生态学调控、种群监测及化学防治提供可靠的理论依据与科技支撑。

植物挥发性物质在昆虫产卵行为中起着关键性作用，是植食性昆虫专一选择的重要信息。圆柏大痣小蜂具有选择祁连圆柏1年生祁连圆柏种实产卵的专性特征。目前植物释放出的挥发性物质对昆虫定位寄主植物起着至关重要的作用已有较深入研究。本项目通过动态顶空吸附法采集祁连圆柏枝叶及不同状态球果挥发性物质，共鉴定出8类，117种化合物。根据GC-EAD和 GC-MS测定结果，确定α-环氧蒎烷、2,4-二甲基苯乙酮、柠檬烯、3-蒈烯、α-松油醇、 桧烯、月桂烯7 种挥发性物质为圆柏大痣小蜂Y型嗅觉仪测定所用标准化合物。通过Y 形嗅觉仪筛选和验证，筛选出月桂烯、α-环氧蒎烷、2,4-二甲基苯乙酮和3-蒈烯4种化合物为作为圆柏大痣小峰雌蜂引诱趋避试验化合物。用Y管嗅觉仪评估由4种化合物组配的11种复配配方引诱趋避雌性圆柏大痣小蜂试验，引诱效果最好的寄主挥发性物质配方为三元配方：3-蒈烯+月桂烯+α-环氧蒎烷(10ug/ul+1ug/ul +100ug/ul)，其次为二元配方：月桂烯+3-蒈烯(10ug/ul+1ug/ul)和月桂烯+α-环氧蒎烷(10ug/ul+10ug/ul)，分别采用三元配方和二元配方做诱捕器诱芯，在祁连圆柏天然林内开展引诱监测试验，3种配方引诱效果均显著高于对照组。本项目实施后，明确了圆柏大痣小蜂产卵生物学行为的信息传递物质，研究结果为圆柏大痣小蜂与寄主的协同进化和圆柏大痣小蜂的生态学调控、种群监测及化学防治提供可靠的理论依据，对解决圆柏大痣小峰对复合信息化合物嗅觉感受机制科学问题研究具有重要的理论意义，对建立高效的产卵引诱化合物配体—受体筛选具有重要实用价值。本项目已发表CSCD论文4篇；在投CSCD论文3篇；获得授权国际发明专利1项、国家发明专利1项，申请国家发明专利1项；完成目前国内仅有的圆柏大痣小蜂完整生活史标本4套。培养毕业硕士生5名，在读硕士生3名，毕业硕士生2名。