棉蚜种群分化及寄主适应机制研究

棉蚜是广泛分布的重要害虫，由于其寄主广、生命周期短、繁殖快、变异快，农业生产中棉蚜的防治依然面临巨大困难。借助分子生物学手段，提升对棉蚜基础生物学、遗传进化的认识是棉蚜防治的一个突破口。前期工作中，我们对棉蚜种群结构进行研究，开发出借助于线粒体序列的分子鉴定技术，引入单倍型的概念来区分棉蚜的生物型，初步掌握棉蚜生物型寄主分布和地理分布。完成棉蚜基因组测序，对主要单倍型基因组重测序结果表明棉蚜生物型的分化已上升到基因组层面。罩笼寄主选择试验证明Hap1棉蚜能通过转录调控来完成跨寄主取食。在此基础上，本项目拟通过对大范围棉蚜群体的基因组重测序和Hap1棉蚜寄主转接试验，揭示棉蚜生物型遗传分化进程和寄主转换中的转录调控，分别从基因组和转录调控层面筛选功能基因组区域及转录调控单元，鉴定寄主利用关键功能基因，为开发依托生物调控和分子调控的棉蚜防治技术打下基础，对研究棉蚜表型重塑及抗性治理有重要意义。

Cotton-melon aphid (Aphis gossypii) is a well-known, widely spread and an important insect pest. Due to its short life cycle, rapid reproduction, cosmopolitan habit and broad range of hosts, the prevention and control, remains most important challenge in agriculture. With the advancement in molecular techniques and population genetics of cotton-melon aphid, has increased the knowledge of its basic biology and turned into a step forward in its prevention and control. In the previous studies, evaluation of population structure of cotton-melon aphid, we had developed molecular identification technology, based on mitochondrial sequencing, introduced the concept of haplotype to distinguish the biotypes of cotton-melon aphid. Initially, grasped the geographical distribution of cotton-melon aphid biotypes and their hosts. The genome sequencing of the cotton-melon aphid genome, has completed. Re-sequencing of the main haplotype genome, has increased the understandings in differentiation of cotton-melon aphid biotypes on genome level. The cage selection experiment showed that Hap1 cotton-melon aphid can complete lifecycle on alternate host through transcriptional regulations. Based on previous results, this project intends to reveal the genetic differentiation process of the cotton-melon aphid biotypes and the transcriptional regulations in host transformation by genome re-sequencing of widespread population of cotton-melon aphid and Hap1 cotton-melon aphid host shifting. Screening of functional genomic regions and transcriptional regulatory units in genomic and transcriptional levels, identifying the key functional genes, responsible for cotton-melon aphids cosmopolitan habit, may be the foundation for the development of cotton-melon aphid control, based on biological and molecular regulation, emphasizing the importance of understanding the phenotypic remodeling and resistance control in cotton-melon aphid.