【摘要】 本文目的是通过对小萤叶甲属部分种类的线粒体COⅠ基因进行比较,探讨小萤叶甲属昆虫进化与寄主植物之间的关系,同时对几种分类地位模糊的昆虫进行分析和归类。测定了我国菱角萤叶甲Galerucella birmanica Jacoby和褐背小萤叶甲Galerucella grisescens Joannis以及小猿叶甲Phaedon brassicae Baly线粒体COⅠ基因720bp序列,并调用GenBank中小萤叶甲属等其他8种昆虫的同源序列,对序列的碱基组成、转换颠换、遗传距离等进行了分析。并以小猿叶甲为外群,分别采用邻接法(NJ)、最大简约法(MP)和贝叶斯推论法(BI)建立这些种的分子系统发育关系。序列分析结果表明:小萤叶甲属昆虫COⅠ基因A+T含量平均为71.8%,存在较强的A+T含量偏向性,氨基酸的变异率为18.3%;小萤叶甲属与外群之间的遗传距离(0.169~0.198)远远大于属内种间的距离(0.001~0.134)。依据分子系统树结果我们推测小萤叶甲属昆虫的进化与寄主植物之间有着显著的关系,在传统分类学上曾隶属于其他属的几种昆虫与小萤叶甲昆虫有着更近的亲缘关系。更多还原

【Abstract】 The aim is to infer the phylogenetic relationships of Galerucella and outgroup Phaedon brassicae Baly beetle species(Coleoptera:Chrysomelidae)and to discuss the relation between the evolution of Galerucella and host plant.The sequences of mitochondrial cytochrome oxidase subunit Ⅰ(COⅠ)gene were sequenced or downloaded from GenBank for the following species:G.birmanica,G.nymphaeae,G.grisescens,G.suturalis,G.capreae,G.lineola,G.viburni,G.pusilla,G.calmariensis,G.tenella,and outgroup P.brassicae.Nucleotides composition,transition and transversion,and genetic distance of a 720 bp segment were analyzed.By using Maximum Parsimony(MP),Neighbor-Joining(NJ)and Bayesian Inference(BI)methods,we constructed the molecular phylogeny of these species based on their COⅠ sequences.The results indicated that average A+T content of COⅠ gene in Galerucella was 71.8%,showing a strong A+T bias.The variation ratio of amino acid was 18.3%.Genetic distances between Galerucella and the outgroup P.brassicae(0.169-0.198)were bigger than those among Galerucella species(0.001-0.134).Molecular phylogenetic trees obtained suggested that there was remarkable relationship between the evolution of Galerucella and host plant,and G.suturalis,G.capreae and G.viburni have closer relationship with species of Galerucella than as defined in traditional taxonomy.更多还原