PaLCuCNV介导的番茄-烟粉虱-寄生蜂三级营养互作关系研究

Papaya leaf curl China virus (PaLCuCNV) is one of the predominant geminivirus species to infect tomato, and the range for the occurrence and damage of PaLCuCNV is being expanded continuously. This PaLCuCNV diseases has severely affected the tomato productions and resulted in huge economic losses. PaLCuCNV is transmitted by the insect vector, Bemisia tabaci. Because of the scarcities of effective control methods and resistance resources, the direct control for plant virus diease is particularly difficult. However, to suppress B. tabaci population is the key to control the PaLCuCNV disease. This project focuses on the tri-trophic interactions among tomato-whitefly-parasitic wasp, and combine the factor of PaLCuCNV, to perform the experiments on the volatiles of healthy or infective tomatoes to attract or repel the whiteflies (B. tabaci B cryptic species, Q cryptic species) or parasitic wasp (Eretmocerus hayati (Zolnerowieh & Rose)), to look for the major semiochemicals for B. tabaci to seach and locate host plants, and to observe the indirect defense responses induced by feeding on healthy or infective tomatoes, as well as to promote the parasitic efficiencies that parasitic wasps parasitise the B. tabaci feeding on healthy or infective tomatoes. The results will explore the ecological mechanisms for PaLCuCNV mediated interactions among tri-trophic system. Our studies will contibute the advances in both scientific and theoretic foundations for enhancing the effciency to control pests by natural enemy and for combining with semiochemicals for ‘pull-push’ control strategy.

番木瓜曲叶病毒（PaLCuCNV）是双生病毒中侵染番茄的优势种病毒，近年来其发生危害范围不断扩大，严重影响我国番茄生产，造成巨大经济损失。PaLCuCNV由烟粉虱传播。有效控制媒介烟粉虱是防治该植物病毒的关键。但长期以来对病毒-媒介昆虫-植物互作机制不清，对植物间接利用天敌防治媒介昆虫的通讯机理缺乏认识，因而缺乏科学的防治理念和技术。本项目以番茄-烟粉虱-寄生蜂三级营养系统为模型，结合PaLCuCNV因子，深入研究健康、感病番茄挥发物对烟粉虱和海氏桨角蚜小蜂的吸引或驱避，烟粉虱搜索定位寄主番茄的主要信息化合物，不带毒和带毒烟粉虱取食健康、发病番茄诱导的间接防御反应？寄生蜂对健康、发病番茄上烟粉虱的寄生效能。以揭示PaLCuCNV介导的多级营养互作的生态学机制，为更好发挥天敌控害效能，结合化学信息物质“推-拉”防治策略，提供重要科学理论基础。

本项目开展PaLCuCNV介导的番茄-烟粉虱-寄生蜂三级营养级的相互作用研究，明确了研究的番茄品种在健康和被PaLCuCNV侵染发病的情况下，对烟粉虱和海氏桨角蚜小蜂选择行为影响不明显，烟粉虱对野生番茄品种选择嗜好度低；β-水芹烯、月桂烯、β-蒎烯、（+）-4-蒈烯、β-石竹烯、α-蒎烯等番茄挥发物对烟粉虱有趋性反应；针刺机械损伤、烟粉虱直接取食都能产生诱发番茄发生间接防御防御反应，诱导萜类化合物含量与成分发生变化；感病番茄和健康番茄影响烟粉虱取食后分泌的蜜露物质成分与含量，带毒烟粉虱分泌的蜜露量均小于健康烟粉虱分泌的蜜露量，海氏桨角蚜小蜂取食烟粉虱蜜露受其取食蜜露前的取食经历影响；海氏桨角蚜小蜂对B、Q隐种烟粉虱都能寄生，但喜欢寄生低龄若虫，寄生带毒番茄与健康番茄叶片上的烟粉虱寄主寄生行为无显著差异，但寄主搜索行为有显著差异，在适宜温度下，当寄主烟粉虱低密度时，海氏桨角蚜小蜂的寄生效率要高，羽化率也高。本项目的研究结果为PaLCuCNV、入侵烟粉虱发生危害的防控提供理论参考。