中国蓟马科昆虫DNA条形码和系统发育研究

Thripidae species is the most important agricultural pest insects around the world, and the vector thrips have been reported are all of Thripidae species. More than 300 species representing 100 genera of Thripidae are recorded in China. Previous study revealed that the morphological characters of some species and genera of Thripidae are very similar which result in judging the taxonomic status of them only by morphological characters is very difficult. Due to the difficulty of morphological identification and the complexity of the taxonomic system of Thripidae, so combining traditional taxonomy with molecular biology studies is urgently needed. 120 to 150 species of Thripidae in China will be sampled, and the molecular gene loci, mitochondrial DNA COI, ribosomal DNA 28S、ITS2 and elongation factor 1-α will be amplified by using PCR and sequenced, providing molecular data for rapid and accurate identification of Thripidae species. Comparing morphological characters of slide specimens with molecular data, the cryptic species and complex species will be discovered, synonymous species will be combined, and the taxonomic status of similar genera and species, also the taxonomic system of Thripidae in China will be clarified, and the phylogenetic relationships of Thripidae in China will be defined. Once the project is implemented, the results will provide taxonomic system of Thripidae in China based on robust evidence at macroevolution (morphological characters) and microevolution (strong phylogenetic evidence) levels, improving the academic level of taxonomic study of Thripidae in China and technical support for the study of biology and control of major Thripidae agricultural pest species.

蓟马科是世界上重要的农业害虫类群之一，已报道的传毒蓟马种类全部包含在该科内。中国记录蓟马科100属300多种。前期研究发现，蓟马科部分属、种形态特征相似，鉴定极其困难，鉴于蓟马科物种形态鉴定的困难性和分类系统的复杂性，迫切需要结合形态分类学和分子生物学手段进行系统研究。本研究拟选取中国蓟马科代表性种类120-150种，进行线粒体基因COI、核基因28S、ITS2和EF1-α的扩增和测序，为快速准确鉴定蓟马科昆虫种类提供分子数据，结合标本的形态特征比对，挖掘隐存种和复合种、合并异名种；明确相似属、种的分类地位，厘清中国蓟马科分类系统；明确中国蓟马科昆虫的系统发育关系。本项目的实施，将为中国蓟马科分类提供宏观（形态特征）和微观（DNA条形码基因序列）相结合的有力证据，提升中国蓟马科分类研究水平，为重大农业有害蓟马生物学及防治研究提供技术支撑。

缨翅目昆虫俗称蓟马是一种微小的昆虫，形态上很难识别，而DNA条形码技术已经成为识别蓟马的一种很好的方法。蓟马科是世界上重要的农业害虫类群之一，已报道的传毒蓟马种类全部包含在该科内。中国记录蓟马科100属300多种，分类还存在很多问题，如同物异名和属种级地位不明确等。前期研究发现，部分属、种形态特征相似，鉴定极其困难，鉴于蓟马科物种形态鉴定的困难性和分类系统的复杂性，迫切需要结合形态分类学和分子生物学手段进行系统研究。为了探讨蓟马科内物种间的系统发育关系，本研究利用线粒体基因COI （cytochrome c oxidase subunit I）、核基因ITS2（internal transcription spacer 2）、28S （28S核糖体DNA）、EF-1α（翻译延伸因子EF-1 α）这4个基因序列对52属76种物种进行了多基因系统发育树的构建。并对蓟马科4个亚科60属112种的COI、ITS2、28S三个基因各112条序列、45属80种的COI、EF1-α、28S三个基因各80条序列以及60属114种的COI和28S三个基因各114条序列进行了联合构建多基因系统发育树。此外，本研究从NCBI数据库中补充下载了82个物种的COI序列，与本研究实验获物种的128条COI序列进行缨翅目物种COI基因的系统发育树重构。本研究还分别构建了蓟马科ITS2（118个物种）、28S（142个物种）和EF1-α（89个物种）三个基因的单基因系统发育树。本研究发现了蓟马科中针蓟马亚科3个新种、1个雄性首描述、2个中国新记录属和7个中国新记录种；获得了针蓟马33个种的140条COI序列，以及30个种的ITS2、28S和EF-1α序列各129 条。蓟马亚科未知种多个、同名异物种3个。本研究的结果丰富了蓟马科物种DNA条形码数据库，并加深了对蓟马科物种进化关系的认识。