高温介导下白木香重大害虫黄野螟生物控制剂暗黑赤眼蜂雄蜂性比调控的分子机制研究

黄野螟是药用植物白木香的重大害虫，暗黑赤眼蜂是申请者首次发现的该虫有效的生物控制剂，该蜂是黄野螟卵期优势寄生蜂。申请者前期研究发现，该蜂在高温条件下性比波动大，影响其对黄野螟的持续控制效果，但目前关于该蜂的性比调控机制尚不清楚。本项目以生产需求为导向，针对白木香生产上黄野螟危害严重的现状，从生物防治的绿色防控技术角度出发，解决生产上应用该蜂的技术瓶颈问题。项目从昆虫生态学和分子水平两个层面开展研究。首先，通过研究高温介导对雄蜂主要生物学指标及繁殖力的影响，明确该蜂性比的生态适应意义及对高温胁迫的响应；其次，采用转录组测序技术筛选高温胁迫导致该蜂精子发生早期差异表达基因，通过定量RT-PCR方法进行体内验证，克隆和表达分析关键候选基因（如Wom/Tra2/Dsx基因），并采用RNAi技术阐明其功能及作用途径，揭示其雄蜂调控后代性比的分子机制。成果为提高该蜂对黄野螟的生物控制效果提供理论依据。

Heortia vitessoides was a major pest of Aquilaria sinensis forests in recent years. Trichogramma pintoi first discovered by the applicant was an important egg parasitoid wasp and as effective biological control agent of H. vitessoides. Our previous research found that the wasp has a large fluctuation in its sex-ratio under high temperature conditions, which affects its continuous control effect on H. vitessoides. However, the regulation mechanism of offspring sex ratio of the wasp is still unclear. In view of the serious damage of H. vitessoides in the planting of A. sinensis and parasitoid wasps as effective biological control agents, this project is demand-driven and solve technical problems in the application of Trichogramma in production. This project will carry out the researches with the insect ecology and the molecular aspects. First, we will clear the effect of high temperature stress on the important biological indicators and the fecundity of males. Clarify the ecological adaptation significance of the wasp sex-ratio regulation and its response to high temperature stress. Then, we will find differentially expressed genes of T. pintoi males caused by high temperature stress using transcriptome sequencing technology and verify by quantitative RT-PCR method. Finally, we will study the role of key candidate genes (such as Wom/Tra2/Dsx genes) using RNAi technology and explore the effect and the molecular mechanism of high temperature stress on the fertility of T. pintoi males. The results will provide a theoretical basis for improving the biological control strategy of H. vitessoides in the future.