烟粉虱物种复合体内隐种间的生殖隔离和分子种系发生研究

The whitefly Bemisia tabaci is widely distributed in the tropical and subtropical regions of the world. In the last 20 years, some B. tabaci have invaded many parts of the world and caused serious damage to crop production. While the genetic diversity and complexity of this whitefly have long been recognized, its species status, in particular whether B. tabaci is one species containing many biotypes or a complex containing many cryptic species, has been a subject of debate. In recent years, substantial progress has been made in studies on the phylogeny and systematics of B. tabaci, and evidence suggests that this whitefly is a species complex containing >28 cryptic species. However, data on reproductive isolation are yet insufficient and the results of phylogenetic analyses have been questioned because they relied on only the COI gene. In this application, we propose to conduct more crossing experiments between putative cryptic species to assess more comprehensively the pattern of reproductive isolation, to sequence the whole mitochondrial genome and some low-copy nuclear genes for >20 putative species, and to conduct a more comprehensive phylogenetic analysis using multiple genes. Finally, data of reproductive isolation and results of phylogenetic analysis will be considered in an integrated manner to obtain new information on the systematics of this species complex, and provide new insights on its classification and nomenclature. It is hoped that this study will provide the basic information of systematics that is essential for the fundamental studies as well as management on this species complex.

烟粉虱Bemisia tabaci广泛分布于全球热带和亚热带地区。近20多年一些烟粉虱入侵世界各地严重危害作物生产。烟粉虱遗传结构的多样性和复杂性早已被关注，但其分类地位，尤其是烟粉虱到底是一个包含多个生物型的种、还是一个包含许多隐种的物种复合体，一直颇受争议。近几年有关烟粉虱的种系发生和系统学的研究取得长足进展，有证据推论其是一个包含至少28个隐种的物种复合体，但生殖隔离证据仍显不足，种系发生分析结果因仅依据COI一个基因而受到质疑。本项目依据上述有关研究面临的问题，一方面继续获取杂交试验数据、更全面地了解该复合体内各支系的生殖隔离程度；另一方面将获取20多个推测隐种的线粒体全基因组和部分核基因的信息，对种系发生做更全面深入的探讨；最后将两方面结果综合分析，以求得对该物种复合体系统发育的深入了解，并对隐种的分类和命名提出新见解，为烟粉虱不同隐种的深入研究和综合治理提供必需的基础信息。

项目组依据项目资助计划书中所计划的研究内容和拟解决的关键科学问题，深入开展了相关研究，取得了以下重要进展：（1）进一步阐明了烟粉虱隐存种复合群内推测隐存种间的生殖隔离状况；（2）获得了烟粉虱隐存种复合群内27个隐存种的线粒体全基因组序列；（3）获得了烟粉虱隐存种复合群内27个隐存种的4个单拷贝核基因的序列；（4）获得了烟粉虱隐存种复合群内20个隐存种的简化基因组信息；（5）利用上述三组基因组数据进行分子系统演化的综合分析，显著深化了对烟粉虱隐存种复合群分子种系发生和进化历史的认识；（6）烟粉虱复合群隐存种的分类和命名取得重要阶段性进展。这些通过项目组在中国境内的研究及广泛深入的国际合作所取得的进展，代表了目前国际学术界有关烟粉虱隐存种复合群系统发育研究的前沿，并为在今后1-2年内最终解决烟粉虱复合群内隐存种的分类和命名提供了坚实的科学基础。在昆虫学和生物学领域国际主流学术期刊发表研究论文7篇，在国家级学报发表论文1篇，培养博士后1名、博士研究生1名、硕士研究生1名，另有3名博士研究生、3名硕士研究生参与了本项目的研究。项目负责人应邀参与了2016年9月在美国召开的第25届国际昆虫学大会的组委会工作，并在专题研讨会上报告了本项目的最新研究进展。