基于COⅠ基因对三种大黑鳃金龟分类地位的研究

Research into the taxonomic status of three kinds of scarabs

本试验将江南大黑鳃金龟Holotrichia gebleri Faldermann分别与东北大黑鳃金龟Holotrichia diomphalia Bates、华北大黑鳃金龟Holotrichia oblita Faldermann进行了杂交试验,得到了F1代成虫,自交得到了F2代,表明F1代的雌雄虫具有正常的生殖力,3种金龟子之间不存在生殖隔离。对这3种大黑鳃金龟的COⅠ基因进行了扩增与测序并构建了系统进化树,结果显示:江南大黑、华北大黑和东北大黑3种鳃金龟的遗传距离相近,分类地差别不显著,与外类群的暗黑鳃金龟Holotrichia parallela Motschulsky在遗传距离和分类地位上差异显著。以上结果表明,江南大黑鳃金龟、东北大黑鳃金龟和华北大黑鳃金龟应为同一个物种的不同地理类群。

Holotrichia gebleri Faldermann was experimentally hybridized, with Holotrichia diomphalia Bates and Holotrichia oblita Faldermann. An F2 generation was then obtained from each F1 generation, demonstrating that males and females of each hybrid population were fertile. Mitochondrial cytochrome C oxidase I （COI ） gene fragments of three parent scarab species were cloned and sequenced and the genetic distance of these sequences analysed. These sequences were used to produce four kinds of phylogenetic trees. The results show that the genetic distance between the three species is similar and that each is distinct from H. parallela Motschulsky. We conclude that H. gebleri, H. diomphalia and H. oblita are three geographic populations of the same species.