稻飞虱迁出种群趋光性暂时抑制时间及机理研究

Rice planthoppers (RPH, Nilaparvata lugens & Sogatella furcifera) are important migratory rice pests in China, depending on its phototaxis, the light trap is an important tool to monitor and early warning its outbreaks. Our previous study found the phototaxis of RPH emigrants was temporarily inhibited during emigration period. However, the temporary inhibition duration, inducment and recurrence factors and internal mechanism need to be revealed. Combining with ethology, cytology and genetics, this proposal aims to elucidate the causal relationship and the action mechanism of temporary inhibition, in order to improve the forecasting accuracy by light traps. The temporary inhibition duration will be examined by the infrared camera when RPH emigrating in wind tunnel, meanwhile the measured duration will be proven by the sticky card trap captures at different heights during the emigration peaks in a rice paddy, combining with the operated search light trap. The ultrastructural features of the compound eyes of inhibited and recovered emigrants will be analyzed by electron microscopy. The genes and metabolic pathways involved in the temporary inhibition of phototaxis will be identified by the transcriptome sequencing technique, attempting to elucidate the molecular mechanism of the temporary inhibition of RPH phototaxis. Implement of this project will provide scientific references for the optimal design of light trap, accurate interpretation of the light trap data and improve the accuracy of RPH forecast.

稻飞虱（褐飞虱和白背飞虱）是水稻上重要的迁飞性害虫，利用其趋光性进行灯光诱虫，是对其监测预警的重要手段。本项目组前期研究发现稻飞虱迁出种群暂时抑制了趋光性，但暂时抑制时间长短、诱发和解除条件及内在机理有待揭示，深刻阐明这些因果关系及其机理，对提高诱虫灯监测预警水平有重要作用。为此，本项目拟联合行为学、细胞学及基因学方法开展研究。利用风洞模拟稻飞虱迁飞，结合红外摄像技术，测定趋光性暂时抑制的时间，并在田间迁出高峰期，在探照灯诱虫器上方不同高度设置粘虫板，对迁出种群诱捕来加以验证；使用电镜技术，分析趋光性暂时抑制及解除后复眼的超微结构变化；并利用转录组技术发掘参与趋光性暂时抑制的相关基因及代谢通路，探讨稻飞虱迁出种群趋光性暂时抑制的分子调控机制。本项目的完成，可为优化设计诱虫灯，准确解读灯诱数据，提高稻飞虱测报水平提供科学依据。

稻飞虱（褐飞虱和白背飞虱）是水稻上重要的迁飞性害虫，利用趋光性进行灯光诱捕是对其监测预警的重要手段。前期研究发现稻飞虱迁出种群很少在当地扑灯，但是关于迁出种群对哪些波长抑制、抑制时长以及内在机理有待深入研究，本项目通过标记释放回收试验表明，在微风和无降水条件下，褐飞虱迁出种群对紫外光（黑光灯）不敏感；利用室内行为学试验表明，褐飞虱迁出种群在外迁起飞之前对紫外光不敏感但对蓝光敏感。利用电镜技术明确褐飞虱小眼视网膜由8个感光细胞构成，并分析光暗适应下的色素细胞移动状态。利用比较转录组学鉴定出3个视蛋白基因，长波视蛋白 (LW opsin)、紫外视蛋白1 (UV1) 和紫外视蛋白2 (UV2)，还鉴定出2个隐花色素基因CRY1和CRY2。UV1和CRY1可能在迁出种群趋光行为过程中发挥了重要作用。研究结果不仅为优化设计诱虫灯，提高稻飞虱预测预报水平，也为深入探索视觉调控稻飞虱趋光行为机制奠定了基础。