基于rDNA ITS1序列的甘肃省叶螨属Tetranychus和全爪螨属Panonychus种群的系统关系

Phylogenetic relationship between spider mite genus Tetranychus and Panonychus based on ribosomal DNA ITS1 sequence in Gansu Province

【目的】明确甘肃省叶螨属和全爪螨属种群遗传多样性及系统发育关系.【方法】对采自甘肃省的不同地理种群及不同寄主的共27个叶螨种群的rDNA ITS1序列进行PCR扩增并测序,利用MEGA 6.0软件分析叶螨不同种群的序列差异情况,采用NJ法构建系统发育树并进行系统关系分析.【结果】共获得27条叶螨rDNA ITS1序列,长度范围在596~688 bp,A、T、C、G平均含量分别为32.5%、31.0%、18.6%,17.9%,A+T含量(63.5%)高于G+C(36.5%)含量,有明显的A/T偏好性.核苷酸多样性为0.128.共检测出9个单倍型.形态学鉴定的截形叶螨(T.truncatus)、二斑叶螨(T.urticae)、山楂叶螨(T.viennensis)、柑橘全爪螨(Pa.citri)4个种在系统发育树中各自成一个单系,朱砂叶螨(T.cinnabarinus)与二斑叶螨(T.urticae)聚合在一起,支持这两者为同一个种的观点.但神泽氏叶螨(T.kanzawai)的系统发生关系还存在争议.【结论】基于rDNA ITS1序列的系统发育分析明确支持5种形态学上鉴定的种的地位,rDNA ITS1对于叶螨种类分子水平的鉴定是一种有效的DNA分子标记,对于未能完全支持的种类需要进一步选取多重分子标记确立其系统地位.

【Objective】 This study was aimed to clarify the genetic diversity and phylogenetic relationships between spider mite genus Tetranychus and Panonychus in Gansu Province.【Method】 The rDNA ITS1 sequences of 27 Tetranychus populations from different geographic populations and different hosts in Gansu were amplified by PCR and sequenced,the sequence differences of mite populations were analyzed with MEGA 6.0 software.The phylogenetic tree was constructed and analyzed by NJ method.【Result】 27 rDNA ITS1 sequences of Tetranychus were obtained,ranging in length from 596 bp to 688 bp.The average contents of A,T,C and G are 32.5%,31.0%,18.6%,17.9% respectively. The A+T content(63.5%) was apparently higher than the G+C content(36.5%),with an obvious A/T counts bias. The nucleic acid diversity was 0.128. There were 9 haplotypes in 27 populations. The four species of T. truncatus,T. urticae,T. viennensis,and Pa. Citri identified by morphology are monophyletic group.T. truncatus and T. cinnabarinus were on the same branch,which supported that they are the same species,and the phylogenesis of T. kanzawai was not well defined. 【Conclusion】 Phylogenetic analysis based on the rDNA ITS1 sequence clearly supports the status of five morphologically identified species. The rDNA ITS1 was an effective DNA molecular marker,of which the unidentified species need to further study by using more molecular markers.