广西南宁地区异常高温胁迫下扶桑绵粉蚧的发育适合度及生理响应机制

Phenacoccus solenopsis as an important invasive pest, has spreaded over most areas in Guangxi. Hibiscus rosa-sinensis, the city flower of Nanning with an important economic value, now is suffering from P. solenopsis harm in Nanning. Since abnormal high temperature occurred frequently in recent years in Nanning, this climate has a significant impact on the pest and its host and promptes the changes of metabolic relationship between the pest and its host. Given that, the project focuses on the direct affects of abnormal high temperature stress on the developmental fitness of P. solenopsis, and the indirect effects mediated by the host plant. Experimental population life table, physiological and biochemical analysis methods will be applied. The key research contents include: 1) the influence of heat stress on the developmental fitness of P. solenopsis; 2) the influence of heat stress on the nutrients and defensive substances of H. rosa-sinensis; 3) the effect of heat stress on the heat tolerant metabolic substance content, protective enzymes and detoxification enzymes activity of P. solenopsis. This project aims to predict the occurrence tendency of the P. solenopsis when abnormal temperature occurs through host-insect metabolism relationship analysis under high temperature stress. It also clarifies the relationship between host defense and P. solenopsis anti-defense under heat stress. The research finally reveals the reproductive strategies and physiological response mechanism of P. solenopsis under high temperature stress. The results will help predict the tendency of this pest under hot weather in Nnaning, Guangxi, and provide scientific reference for regional disaster reduction management of this pest.

扶桑绵粉蚧为一种重要入侵害虫，在广西大部分地区已有分布。其在南宁地区严重危害朱槿，而朱槿为南宁市市花，具有重要的经济价值。近年来，南宁地区异常高温天气频发，这种气候将对该害虫及其寄主产生显著影响，促使两者代谢关系发生变化。本项目围绕“南宁地区异常高温胁迫对扶桑绵粉蚧发育适合度的直接影响，及通过寄主植物介导的间接影响”这一主题，采用实验种群生命表、生理、生化分析等方法，重点研究：1）高温胁迫对扶桑绵粉蚧发育适合度的影响；2）高温胁迫对朱槿营养物质和防御物质含量的影响；3）高温胁迫对扶桑绵粉蚧耐热代谢物质含量、保护酶、解毒酶活性的影响。通过高温胁迫下寄主-昆虫代谢关系的解析，预测异常高温发生时，扶桑绵粉蚧种群发生趋势；明确高温胁迫下，该害虫与寄主的攻防关系，揭示高温胁迫下，该害虫的生殖策略及生理响应机制。研究结果将有助于预测该害虫在广西南宁地区高温气候下的发生趋势，为区域减灾治理提供科学参考。

扶桑绵粉蚧为一种重要入侵害虫，在广西大部分地区已有分布。近年来，南宁地区异常高温天气频发，这种气候将对该害虫及其寄主产生显著影响，促使两者代谢关系发生变化。通过高温胁迫下寄主-昆虫代谢关系的解析，预测异常高温发生时，该粉蚧种群发生趋势；明确高温胁迫下，该害虫与寄主的攻防关系，揭示高温胁迫下，该害虫的生殖策略及生理响应机制。研究结果将有助于预测该害虫在广西南宁地区高温气候下的发生趋势，为区域减灾治理提供科学参考。.经处理的1龄若虫，随温度升高，雌虫和雄虫的发育历期、净增值率、内禀增长率、周限增长率先增后减，周限增长率都大于1，平均世代、种群加倍时间先减后增。经处理的1、2、3龄和雌成虫死亡率均提高，随温度升高，各龄期的最终平均产仔量先升后降，成虫体型增大、含水量增加。温度升高利于该粉蚧种群发展，但极端高温减缓种群发展；高温对该粉蚧存活造成了短期实时的影响，并且会促进该粉蚧生长，但极端高温又不利于各龄期存活和生长。.叶片中的蛋白含量随温度升高呈下降趋势；可溶性糖、单宁含量随温度升高呈上升趋势；C含量随温度升高先升后降，N含量随温度升高先降后升，C/N随温度升高先升后降。高温胁迫下该粉蚧发育历期与可溶性糖、蛋白、单宁含量、C/N均无显著相关性。高温胁迫下3龄若虫的死亡率与单宁含量显著负相关，与C/N显著正相关。可溶性蛋白含量、C/N与该粉蚧体型、含水量呈负相关；可溶性糖、单宁含量与该粉蚧体型、含水量呈正相关。.随温度升高，扶桑绵粉蚧体内蛋白含量呈升高趋势，POD活力随温度升高呈下降趋势，CAT活力、SOD活力随温度升高先升后降。扶桑绵粉蚧在应对高温胁迫中，体内生理机制采取相应的措施（保护酶活性升高）来抵御外部高温的伤害，但是当温度超过其耐受范围，其体内生理机制遭到破坏。