基于核基因EF-1a序列的盾蚧亚科7个属的系统发育  

Study on the phylogeny of seven genera of Diaspidinae based on EF-1a sequences

作　　者：魏久锋[1] 冯纪年[1] 王鹏[1] 黄素凡[1] 

机构地区：[1]西北农林科技大学植物保护资源与病虫害防治教育部重点实验室,陕西杨凌712100

出　　处：《西北农林科技大学学报（自然科学版）》2009年第11期149-155,共7页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(30870324);西北农林科技大学创新性实验计划项目(2008022A)

摘　　要：【目的】对盾蚧亚科昆虫的基因序列进行研究,探讨EF-1a基因在该亚科昆虫中的分子进化机制,为我国盾蚧亚科昆虫的分类与鉴定提供理论依据。【方法】以EF-1a为目的基因,对分布于中国的盾蚧亚科雪盾蚧属、白轮蚧属、并盾蚧属、盾蚧属、矢尖蚧属、拟轮蚧属和围盾蚧属7个属13种蚧虫以及2个外群的EF-1a基因进行特异性扩增和测序。使用ClustalX1.83和MEGA4.0系统发育分析软件,对所得DNA序列的碱基组成、碱基替换、遗传距离等进行分析;通过碱基替换饱和性分析进行了信号检验;在MEGA4.0软件中采用最大简约法、邻接法和最小进化法对盾蚧亚科7属的系统发育关系进行分析。【结果】(1)盾蚧亚科7属的EF-1a序列中,T、C、A、G的平均含量分别为23.5%,25.6%,25.5%和25.4%,A+T的含量为49%,G+C的含量为51%。(2)转换频率是颠换频率的1.3倍,转换主要发生在A与G之间,颠换主要发生在A与T之间。(3)碱基替换饱和性分析显示,EF-1a数据集有较强的系统发育信号。系统发育树的结果显示,白轮蚧属、并盾蚧属和雪盾蚧属属同一支,盾蚧属和矢尖蚧属属同一支,围盾蚧属和拟轮蚧属属同一支。【结论】EF-1a基因是盾蚧亚科属级分类单元分子系统发育的有效基因标记之一。[Objective] The research discussed the molecular evolution based on EF-1α sequences in Diaspidinae by studying the sequence of Diaspidinae, which will be very useful for taxonomy and identification of Diaspidinae species occurring in China. [Method] In this study,the phylogenetic relationships of the seven genera of Diaspidinae have been analyzed by using nuclear EF-1α sequences from 7 genera that are Chionaspis,Aulacaspis, Pinnaspis, Diaspis, Unaspis , Pseudaulacaspis and Fiorinia consisting of 13 species and other two outgroups in China. The base frequency, base substitution and genetic distance of DNA sequence have been analyzed by using some biosoftwares such as. ClustalX 1.83, MEGA 4.0 and so on. Phylogenetic information has been tested via base substitution saturation analysis. Phylogenetic trees have been constructed with three methods, maximum parsimony（MP）, neighbor-joining（NJ） and maximum likelihood （ML） on the software MEGA 4.0. [Result] （1）The average content of T,C,A and G of EF-1α of seven genera of Diaspidinae is 23.5% ,25.6% ,25.5% and 25.4% respectively. A＋T content is 49% while G＋C content is 51%;（2）The transition （si） is 1.3 times more than the transversion （sv） of seven families of Diaspidinae. Ti substitution mainly occurs between A and G and Tv usually occurs between A and T. （3） All the phylogenetic trees （NJ,MP and ME） show essentially the same topology,and that the lineages and the sublineages on the trees are linked tightly consistent with the taxonomically defined families and genera based on morphologies. [Conclusion] The gene is a valid one which can be applied in molecular phylogeny on genus of Diaspidine.

关 键 词：盾蚧亚科 核基因 EF-1α基因 分子系统学 

分 类 号：S433.3[农业科学—农业昆虫与害虫防治]