基于线粒体COⅠ基因的三江源草原毛虫金小蜂分子鉴定与系统发育分析

Molecular identification and phylogenetic analysis of Pteromalussanjiangyuanicus Yang based on the mitochondrial COⅠgene

【目的】三江源草原毛虫金小蜂在形态学水平上已被鉴定为草原毛虫蛹期的寄生蜂新种。本研究拟从分子标记水平再次对三江源草原毛虫金小蜂进行物种辅助鉴定,探究其在小蜂总科中的系统发育关系。【方法】利用分子生物学手段对三江源草原毛虫金小蜂线粒体COⅠ基因进行扩增、测序与分析,并采用邻接法构建系统发育N-J树。【结果】三江源草原毛虫金小蜂线粒体COⅠ基因校正后的长度为812 bp,A、T、C、G碱基含量分别为34.36%、42.61%、10.59%、12.44%,AT含量显著高于GC含量,具有明显的AT偏好性;三江源草原毛虫金小蜂与蝶蛹金小蜂COⅠ基因相似度最高,遗传距离最小,表明三江源草原毛虫金小蜂与蝶蛹金小蜂亲缘较近,因此推断三江源草原毛虫金小蜂可能属于金小蜂科物种;三江源草原毛虫金小蜂先后与Eupelmus sp.、Sycoscapter sp.、Idiomacromerus sp.、Diaziella bizarre、Eurytoma sp.聚为一支,且与Idiomacromerus sp.+(Diaziella bizarre+Eurytoma sp.)+(Eupelmus sp.+Sycoscapter sp.)形成姊妹群。【结论】本研究从分子标记水平揭示了三江源草原毛虫金小蜂与金小蜂科物种的亲缘关系较近,支持了三江源草原毛虫金小蜂的形态学物种鉴定结果,为更深入地研究三江源草原毛虫金小蜂系统发育提供了科学依据,对草原毛虫的生物防治具有重要意义。

【Aim】Pteromalus sanjiangyuanicus Yang has been identified by morphology as a new parasitic wasp species of the pupal stage of the Gynaephora qinghaiensis.The aim was to further identify P.sanjiangyuanicus at the molecular marker level and explore its phylogenetic relationships within Chalcidoidea,【Method】In this study,we sequenced and analyzed the mitochondrial COⅠgene of P.sanjiangyuanicus and constructed a phylogenetic N-J tree by the neighbor-joining method.【Result】The length of the mitochondrial COⅠgene of P.sanjiangyuanicus was 812 bp after correction,and the contents of A,T,C and G bases were 34.36%,42.61%,10.59%and 12.44%,respectively.The content of AT was significantly higher than that of GC,showing obvious AT bias.The COⅠgene similarity between P.sanjiangyuanicus and Pteromalus puparum was the highest,and the genetic distance was the smallest,indicating that P.sanjiangyuanicus and Pteromalus puparum are closely related.Therefore,it was concluded that P.sanjiangyuanicus may belong to the family Pteromalidae.P.sanjiangyuanicus clustered with Eupelmus sp.,Sycoscapter sp.,Idiomacromerus sp.,Diaziella bizarrea,and Eurytoma sp.and formed a sister group with Idiomacromerus sp.+(Diaziella bizarrea+Eurytoma sp.)+(Eupelmus sp.+Sycoscapter sp.).【Conclusion】In this study,analysis at the molecular marker level revealed the close genetic relationships between P.sanjiangyuanicus and Pteromalidae species,which supported the morphological species identification results of P.sanjiangyuanicus and provided a scientific basis for further research on the phylogeny of P.sanjiangyuanicus,which will be of great significance for the biological control of G.qinghaiensis.