基于ITS2序列的12种苔藓植物亲缘关系分析

以尖叶薄鳞苔为外类群,利用ClustalX 2.0和MEGA 4.1软件对12种苔藓植物的ITS2序列进行比对和分析,构建分子系统树.结果表明,12种苔藓植物的ITS2序列长度在432-493bp之间,排序后总长度为540 bp,其中变异位点305个,信息位点200个.12种苔藓植物的遗传距离在0.016～0.472之间,平均遗传距离为0.309.利用MP法建立的系统树显示,12种苔藓植物分为3组,其中7个丛藓科物种聚为一组,3个青藓科物种聚为一组,2种灰藓科植物聚为一组,序列分析结果与形态学分类结果一致,表明ITS2可用于苔藓植物的亲缘关系分析.

The Phylogenetic Relationship Analysis of 12 Bryophyte Species Based on ITS2 Sequence

Using Leptolejeunea elliptica as outgroup,ITS2 sequences of 12 bryophyte species were blasted and analyzed to construct the phylogenetic tree using ClustalX 2.0 and MEGA 4.1 software.The results showed that the lengths of ITS2 in 12 bryophytes were 432～493 bp;and the total length of sequence was 540 bp after alignment,including 305 variable sites and 200 informative sites.The genetic distance among the species was 0.016～0.472 with an average of 0.309.In the MP tree,7 Pottiaceae species,3 Brachytheciaceae species and 2 Hypnaceae species were clustered into separate groups,which were consistent with the morphologic identification,indicating that ITS2 could be used for the bryophytes relationship analysis.