核桃举肢蛾性信息素与交配行为化学通讯研究

Atriglans hetaohei Yang (Lepidoptera: Heliodinidae) is a destructive pest of walnuts in China, and its larvae specially bore young fruits of walnuts and cause major economic losses for walnut industry in China. This pest, a typical fruit borer, is difficult to control because of its cryptic damaging habits, but utilization of sex pheromone is considered to be a hopeful effectient way in the control of this pest. However, the circadian rhythm of the sex pheromone synthesis and release, the chemical communication of mating behavior and the key activitive component of the sex pheromone of A. hetaohei during reproductive period still remain unknown. This program, basing on our previous studies, will study and identify the sex pheromone compenents of A. hetaohei by collecting females in sexual excitement from the walnut forests using GC-MS and GC-EAD methods. In addition, the key activitive component, the percentage of each component and field trapping activity of the sex pheromone will be studied using organic synthesis, EAG, Y-tube olfactometer, and field trapping tests. Furthermore, the relationships among the mating behavior of A. hetaohei, its host plant and the abiotic environmental factors (such as space, temperature, humidity, and illumination) will also be investigated, in order to reveal the effect of host plant walnut volatiles on chemical communication of mating behavior and clarify its mechanism of chemical communication of mating behavior of A. hetaohei. The research results are hopeful to provide theoretical basis for efficient and convenient field monitor and control of A. hetaohei.

核桃举肢蛾是专门危害核桃的重要蛀果害虫，由于为害隐蔽而难于防治，每年都对我国核桃产业造成重大损失。性信息素防治是控制蛀果害虫的一种有效途径，但目前关于核桃举肢蛾在繁殖过程中的性信息素合成、释放及相关化学通讯尚不明晰，性信息素的关键成分更未确定。本项目拟在前期研究基础上，通过野外收集处于性兴奋期的雌虫性信息素物质，利用气相色谱-质谱联用(GC-MS)、气相色谱-触角电位联用（GC-EAD）等技术鉴定核桃举肢蛾性信息素组分，然后通过有机合成、触角电位(EAG)、Y形嗅觉仪和林间诱捕试验，明确其性信息素关键活性成分、比例及林间引诱活性；此外，通过探讨核桃举肢蛾交配行为与寄主植物和非生物环境因子（空间、温度、湿度、光照）间的相关性，揭示寄主植物挥发物对核桃举肢蛾交配行为化学通讯的影响，阐明其交配行为的化学通讯机制。相关研究结果有望为核桃举肢蛾的林间监测和防控技术提供理论依据。

本项目综合运用行为学、化学生态学、分子生物学等研究方法，对核桃举肢蛾求偶交配行为、性信息素的合成释放规律、性信息素提取、活性化合物鉴定及植物气味物质对核桃举肢蛾行为的影响等进行了研究。研究表明田间条件下核桃举肢蛾成虫羽化高峰期集中在5月下旬至6月上旬，具有明显的昼夜节律，成虫下午16:00至傍晚19:30活跃，在此期间雌虫出现求偶召唤状态及交配行为。而在室内条件下雌虫无明显的求偶行为，环境因素（空间、温度、湿度、光周期）对其求偶交配行为影响显著；获得了核桃举肢蛾线粒体基因序列，通过序列比较，明确了核桃举肢蛾分类地位，为核桃举肢蛾性信息素关键组分的发现提供了重要线索；通过GC/MS检测雌虫性腺体提取物，结合EAG试验等最终确定核桃举肢蛾雌虫性腺体内含有E-5-16:Ac成分，并且发现只有在产卵器伸出体外时，才能提取检测到性信息素成分，从而明确了核桃举肢蛾性信息素合成释放规律；通过Wttig反应优化、催化偶联反应，合成了多种核桃举肢蛾性信息素相关候选化合物；通过EAG试验、“Y”型嗅觉仪试验及田间引诱试验确定了E-5-16:Ac为其主要性信息素组分；明确了核桃举肢蛾雌雄成虫对不同植物挥发物的EAG反应存在差异，雌虫对多数供试化合物的EAG反应强度大于雄虫，雌虫对多数植物挥发物更敏感具有重要生态适应意义；明确了雌雄成虫触角上存在毛形感器等9种感器类型及触角鳞片上的小孔、纵肋、横梁和小梁等细微结构。此外，利用核桃举肢蛾发生时期监测结果确定了防治关键时期为5月中下旬，改变了当地6月中旬才施药防治的传统习惯，开展了树干注药等多种防治措施研究，集成了核桃举肢蛾关键防控技术。本项目所取得的研究结果揭示了核桃举肢蛾求偶交配行为规律，环境因素与寄主对其交配行为的影响，明确了核桃举肢蛾性信息素合成、释放规律，性信息素关键活性组分及防控关键技术。为进一步深入探讨其求偶与交配行为、寄主选择化学通信及防治具有重要的理论与实践指导意义。