热区耐热型害虫瓜实蝇对高温胁迫的防御与生殖对策机制

Bactrocera cucurbitae (Coquillett), i.e. melon fly, is one of the major pests of fruit and vegetable crops, wide distribution in tropical and subtropical regions. High-temperature can greatly affect the development and reproduction of the melon fly. Through preliminary study, we find that the range of high temperature and treatment time are currently two major influencing factors on the development and reproduction of melon fly. In particular, the two factors contribute to the “hormesis reaction” that significantly stimulates melon fly to lay eggs. Targeted at the defensive and reproductive strategies of melon fly under the high-temperature stress and focusing on the “hormesis reaction” of short-term high temperature on melon fly, this study employs the methods of population ecology, morphology, molecular biology, etc. to explore the following issues: 1) comparing the biological effects of high temperature on the successive generation of melon fly, discussing the reproducibility of the “hormesis reaction” in different generations, and discussing whether there is a “maternal reaction”; 2) using vitellin-related gene sequences to analyze its expression changes and functions and reveal the molecular regulation by high temperature in the reproduction of melon fly; 3) making a comprehensive display of biological and molecular biological results and determining the reproductive and physiological response mechanisms of melon fly, a heat-resistant pest living in the tropical and subtropical regions, under high temperature stress. The above studies will reveal the the defensive and reproductive strategies mechanisms of melon fly of different generations in high temperature stress, and provide the scientific basis for expounding the infestation regularity of melon fly and developing effective control strategies.

瓜实蝇是热带亚热带区域果蔬类作物的重要害虫，高温对其生长发育和繁殖有重要影响。本项目前期研究发现，高温幅度和持续时间两因素共同影响当代瓜实蝇的生长发育和繁殖，甚至产生明显刺激瓜实蝇产卵的“毒物兴奋反应”，锁定高温胁迫下瓜实蝇的防御与生殖对策关键科学问题，采用种群生态、形态学、分子生物学技术等研究方法，以短时高温对瓜实蝇产生的“毒物兴奋效应”为主线，重点开展如下研究：1）比较高温对瓜实蝇连续世代的生理学影响，探讨“毒物兴奋效应”不同世代的再现性和阐明是否出现“母代效应”；2）利用已获卵黄蛋白相关基因序列，分析其表达动态及其功能，揭示高温对瓜实蝇生殖的分子调控；3）综合表观生物学和分子生物学等结果，确定热区耐热型害虫瓜实蝇对高温胁迫的防御和生殖对策机制。上述研究将为阐明高温季节瓜实蝇危害规律及制定有效控制策略等提供科学依据。

防御与生殖对策是昆虫应对气候变暖的重要策略，不仅影响个体的存活、发育和繁殖，还直接影响种群的发展。瓜实蝇是热带亚热带区域果蔬类作物的重要害虫，高温对其生长发育和繁殖有重要影响。本项目锁定高温胁迫下瓜实蝇的防御与生殖对策关键科学问题，采用种群生态、形态学、分子生物学技术等研究方法。明确了短时高温对瓜实蝇连续世代的生理效应。揭示了高温对瓜实蝇生殖的分子调控。阐明了热区耐热型害虫瓜实蝇对高温胁迫的防御和生殖对策机制。（1）研究表明了高温强度和频次两种因素共同对瓜实蝇连续世代生长发育和存活产生影响。（2）研究表明了Vitellogenin receptor基因在高温背景下对瓜实蝇产卵行为的分子调控中具有重要作用。（3）通过整合表观生物学和分子生物学等结果，表明了随着气候变暖，短时高温微环境情形出现频次增多，瓜实蝇在应对短时高温会引起表观生物学（如生长发育和存活）和分子生物学（转录、表达等）一系列改变，我们应该引起重视。本项目所得结果在气候变化对昆虫生物学和生态学研究方面具有一定的理论和实际意义。研究结果和所得数据在研究气候变化对瓜实蝇生态学的影响，以及预测气候变化下瓜实蝇的种群动态及提高气候变化条件下害虫预测水平等方面具有潜在的应用价值。