根据ITS序列证据重建防己科蝙蝠葛族的系统发育

Phylogeny of the tribe Menispermeae (Menispermaceae) reconstructed by ITS sequence data

研究了国产防己科蝙蝠葛族trib .Menispermeae 9属 2 0种和外类群青牛胆族trib .Tinosporeae 2属 3种植物完整的ITS(包括 5.8SrDNA)序列。trib .Menispermeae的ITS长 52 7～ 60 1bp ,排序后长 667bp。当gap处理为missing时具 2 81个有信息位点。PAUP软件分析结果表明 :①trib .Menispermeae是一个单系类群 ,该分支得到bootstrap 1 0 0 %的支持 ;②确定了存疑种Pachygonevalida的系统学位置 ,该种是Coc culus属的成员 ;③Sinomenium和Menispermum两属有很近的系统学关系 ,组成族内稳定的一支 ,它们的ITS序列同源性极高 ,ITS1比族内其它属长 41～ 73bp ;④Stephania和Cyclea也是系统发育关系很近的两个类群。前者具两个主要分支 ,其ITS1、ITS2的G +C含量差异较大 ,在种类组成上 ,该两大支与传统上Stephania属内处理的 2个亚属──千金藤亚属subgen .Stephania和山乌龟亚属subgen .Tuberiphania基本一致 ;Cyclea属内种间的ITS序列差异小 ,同源性极高。

The phylogeny of the tribe Menispermeae (Menispermaceae) represented by 20 species of 9 genera in China, was reconstructed based on sequence analysis of the internal transcribed spacers (ITS) (including ITS1, ITS2, and 5.8S rRNA gene ) of nuclear ribosomal DNA. Three species of two genera in the tribe Tinosporeae were designated as outgroups. Direct PCR sequencing method was used in the study. The sizes of ITS within trib. Menispermeae range from 527 to 601 bp. The aligned length is 667 bp, which provides 281 phylogenetically informative sites when gaps are treated as missing. The results of phylogenetic analyses show that: ① trib.Menispermeae is a monophyletic group strongly supported by a bootstrap value of 100%; ②Pachygone valida, whose systematic position was uncertain in the previous classification, should be placed in the Cocculus. ③Sinomenium and Menispermum are two close genera of the tribe. Their sequcences are very similar to each other, with ITS1 having 41 to 73 bp longer than that of the other genera in trib.Menispermeae. ④Stephania and Cyclea are also closely related. The former forms two major clades, which are approximately consistent with the two traditional subgenera: subgen. Stephania and subgen. Tuberiphania. The species of Cyclea are mutually little diverged in complete ITS sequences, and they comprise a sister clade to the genus Stephania.