橡实象虫及其近缘种基于线粒体DNA COⅡ基因的分子系统学研究  

Molecular Systematics of Acorn Weevil and its Allied Species Based on COⅡ Gene of Mitochondrial DNA

作　　者：杨瑞生[1] 姜义仁[1] 石生林[1] 刘彦群[1] 夏润玺[1] 秦利[1] 

机构地区：[1]沈阳农业大学生物科学技术学院,沈阳110866

出　　处：《蚕业科学》2010年第4期577-583,共7页ACTA SERICOLOGICA SINICA

基　　金：辽宁省教育厅高校科研项目(No.L2010511);沈阳农业大学国家自然科学基金启动基金项目(No.20092006);现代农业产业技术体系建设专项(蚕桑);植物病虫害生物学国家重点实验室开放基金项目(No.SKL2010OP07)

摘　　要：橡实象虫(Curculio arakawai)是危害柞树果实(橡实)和嫩芽的主要害虫。基于探索害虫的系统发育和遗传进化机制的目的,以线粒体DNA(mitochondrial DNA,mtDNA)编码的细胞色素氧化酶Ⅱ(cytochrome oxidaseⅡ,COⅡ)基因作为分子标记,对橡实象虫及10个近缘种昆虫进行分子系统学研究。序列分析表明:橡实象虫及10个近缘种的mtDNA COⅡ基因序列全长687bp(不同橡实象虫样本获得的目的基因在GenBank的登录号包括GU945544、GU945545、GU945546),共编码228个氨基酸;mtDNA COⅡ基因表现出明显的A+T含量偏向性,密码子不同位点碱基的使用也存在明显的A+T含量偏向性,mtD-NA COⅡ基因的碱基颠换数总体上高于转换数,颠换主要发生在A←→T间,转换主要发生在T←→C间。遗传变异分析表明,橡实象虫及10个近缘种的核苷酸多态性位点百分率为39.7%,氨基酸突变率为30.3%。分别采用UPGMA法、NJ法和MP法构建橡实象虫及10个近缘种间的COⅡ基因系统进化树,各物种间的拓扑关系虽然稍有差异,但系统进化关系却完全一致,即物种间分别以所在的属聚在一起,形成Curculio、Ceutorhynchus和Peritelus3个属群,其中Curculio属和Ceutorhynchus属的系统进化关系较近,二者聚在一起形成一大支,而Peritelus属单独形成一支。Acorn weevil （Curculio arakawai） is the major pest damaging oak fruit （acorn） and tender buds of the oak tree.In order to explore phylogenetic and genetic evolutionary mechanisms of the pest,molecular systematics of acorn weevil and its 10 allied insect species were studied using cytochrome oxidaseⅡ （COⅡ） gene of mitochondrial DNA （mtDNA） as the molecular marker.Sequence analyses indicated that the full-length mtDNA COⅡ gene of all tested species is 687 bp long,encoding 228 amino acids （GenBank accession No.of COⅡ gene from different acorn weevil samples include GU945544,GU945545 and GU945546）.The average content of A,T,G and C in mtDNA COⅡ gene of a-corn weevil and its allied species show a strong A＋T bias.The use of bases in different positions of codons also shows an obvious A ＋ T bias.Generally,there are more bases from transversion than from transition in mtDNA CO Ⅱ gene.Most transversional base pairs occur between A and T,and most transitional base pairs occur between T and C.Genetic variation analysis revealed that,in the mtDNA COⅡ gene of acorn weevil and its 10 allied species,the percentage of nucleotide polymorphic site reaches 39.7%,with an amino acid mutation rate of 30.3%.Molecular phylogenetic trees constructed using UPGMA,NJ and MP methods are highly consistent with each other,though there is slight difference in the topological relationship between various species.In all the constructed trees,C.arakawai and its allied species were clustered together according to different genera,forming Curculio,Ceutorhynchus and Peritelus groups.Genera Curculio and Ceutorhynchus form a large clade together because of their closer phylogenetic relationship,while genus Peritelus forms a separate clade.

关 键 词：柞树害虫 橡实象虫 近缘物种 线粒体DNA COⅡ基因 序列分析 多态性 分子系统树 

分 类 号：S763.38[农业科学—森林保护学] Q78[农业科学—林学]