基于CO Ⅰ、CO Ⅱ和Cyt b基因探讨沙棘木蠹蛾和榆木蠹蛾的种间关系

Genetic Relationship between Holcocerus hippophaecolust and H. vicarious Based on CO Ⅰ 、CO Ⅱ and Cyt b Genes

沙棘木蠹蛾(Holcocerus hippophaecolust)和榆木蠹蛾(H.vicarious)为木蠹蛾科(Cossidae)线角木蠹蛾属(Holcocerus)的近缘种,二者形态相似,难于进行区分。本文基于线粒体COⅠ、COⅡ和Cyt b基因片段,对我国不同种群的沙棘木蠹蛾和榆木蠹蛾进行遗传差异分析,以探讨二者之间的亲缘关系。遗传距离分析表明,沙棘木蠹蛾和榆木蠹蛾在COⅠ、COⅡ和Cyt b 3个片段的遗传差异分别为0.009,0.001和0.062,仅相当于二者种内遗传差异均值范畴,远远低于同属的种间遗传距离均值,表明两种昆虫之间存在高度的遗传相似性。两种木蠹蛾在3个基因位点共检测到6个共享单倍型,占单倍型总数的四分之一,且共享单倍型分布不受地理距离限制,显示两个种的种群之间尚未完全分化。系统发育树分析中,沙棘木蠹蛾和榆木蠹蛾在3个基因序列均未构成独立分支,而是形成了混合集群。介于沙棘木蠹蛾和榆木蠹蛾之间极高的遗传相似性,对二者之间的亲缘进化关系进行了讨论。

Holcocerus hippophaecolust and H.vicarious are closely related species of Holcocerus （Lepidoptera：Cossidae）.It is difficult to distinguish them based on morphological characters.This research aims to explore the genetic relationship between H.hippophaecolust and H.vicarious from various populations based on partial mitochondrial DNA （mtDNA） COⅠ,COⅡand Cyt b genes.The genetic distance between H.hippophaecolust and H.vicarious was only 0.009,0.001and O.062 for COⅠ,COⅡand Cyt b,respectively,which were found close to the mean conspecific divergence and much lower than the mean congeneric genetic distance.The genetic distance estimated in this study showed highly genetic similarity between the two insect species.6 of 24 total haplotypes are observed as shared haplotypes in 3 mtDNA genes of 2 insect species.Shared haplotypes happened among different populations suggest that the two species are not fully differentiation.Phylogenetic analysis of seven Cossidae species indicates that H.hippophaecolust and H.vicarious formed complex instead of independent branches in all 3 phylogenetic trees.We discussed the possible evolutionary relationship between H.hippophaecolust and H.vicarious based on our current results.