两种基因型褐飞虱群体的遗传调节及其分子机制

Population regulation is one of the foundational items in population ecology, and is also the basis determining population dynamics of insect pests. Because of lack of experimental materials, genetic regulation of insect populations was rarely reported. Here, using high- and low-fecundity genotype of the brown planthopper (BPH) Nilaparvata lugens as materials, genetic regulation of BPH populations in these two genotypes will be studied. Then, the effects of environmental factors (high temperature and resistant rice variety) on BPH population growth of the two genotypes will be studied and compared. Finally, through measurement of BPH hormones (20E, juvenile hormone, etc) and phosphorylation of fecundity-related proteins such as AKT, AMPK and FOXO, as well as sequencing and analysis of transcriptome, we will study signaling pathways and molecular mechanisms involved in the population regulation of the two BPH genotypes via density effect and environmental factors. The novelty of this proposal lies in the pioneer study of genetic regulation of agricultural insect pests with two genotypes and its molecular mechanisms. The finding gained is helpful for understanding the molecular mechanism of population outbreak of agricultural insect pests such as BPH, and is also of importance for forecasting and management of the pests.

种群调节是种群生态学的一个核心问题，也是决定害虫数量动态的基础。由于实验材料缺乏，关于昆虫种群的遗传调节鲜有报道。本项目以褐飞虱高繁殖力和低繁殖力基因型群体为实验材料，研究其遗传调节规律；然后，比较研究环境因子（高温和抗虫水稻品种）对2种基因型褐飞虱群体数量增长的影响；最后，通过褐飞虱激素（20E、保幼激素等）和繁殖力相关蛋白（AKT、AMPK和FOXO等）磷酸化测定以及转录组测序和分析等手段，研究2种基因型群体通过密度效应和环境因子调节其数量的信号通路及分子机制。创新之处在于：率先研究农业害虫2种基因型群体的遗传调节及其分子机制。研究结果有助于解析褐飞虱等农业害虫种群暴发的分子机制，对其预测预报和针对性防控也有重要指导意义。

种群调节是种群生态学的一个核心问题，也是决定害虫数量动态的基础。由于实验材料缺乏，关于昆虫种群的遗传调节鲜有报道。本项目以褐飞虱高繁殖力和低繁殖力基因型群体为实验材料，研究其遗传调节规律。结果表明，两种基因型褐飞虱群体除繁殖力存在极显著差异外，高繁殖力基因型群体的雌成虫体重和蜜露分泌量也显著高于低繁殖力基因型群体，而低繁殖力基因型群体的卵孵化率更高。阐明了两种基因型褐飞虱的若虫密度效应，其种群动态变化符合种群遗传调节学说。抗虫水稻品种IR36和密度效应互作对高繁殖力基因型群体的影响较大，低繁殖力基因型群体的环境耐受力更强，种群增长更稳定。多巴胺的生物合成是两种基因型褐飞虱应对密度变化时影响其繁殖力的关键调控因子，酪氨酸羟化酶基因Nlpale为其中的关键因子。已发表学术论文3篇，投稿Molecular Ecology论文1篇。完成了计划研究内容和目标。