国产堇菜属的分子系统学研究

Molecular Systematics of Genus Viola L. in China

摘要:

利用基于ITS序列的分子系统学对国产堇菜属(Viola L.)进行了系统发育重建，选择Hybanthus concolor和鳞隔堇(Scyphellandra pierrei)作为外类群，对国产堇菜属植物54种1亚种共66个序列进行分析。分子系统树中获得强烈支持的中国堇菜属属下组级分类群有Sect. Viola、Sect. Diffusae、Sect. Bilobatae、Sect. Vaginatae。Subgen. Melanium与Sect. Viola和Sect. Trigonocarpae聚在一起，说明它们的亲缘关系较近，但Sect. Trigonocarpae支获得的支持率较低。分子系统树证实了Subgen. Dischidium与Subgen. Chamaemelanium的近缘关系，但不支持根据距的长短将Subgen. Dischidium划分为Sect. Longicalcaratae和Sect. Brevicalcaratae的处理。而Pinnatae类群应该作为Sect. Adnatae下的一个亚组处理。根据分子系统发育和形态学特征对V. lucens、V. magnifica、V. dissecta、V. yunnanensis等的分类地位进行了重新评价。

Abstract:

The internal transcribed sequence of the nuclear ribosomal DNA (nrDNA-ITS) was chosen as the target sequence to resolve the phylogeny of the genus Viola in China. 66 sequences (39 of which were reported for the first time) of 55 ingroup taxa were collected, with Hybanthus concolor and Scyphellandra pierrei as outgroups. Molecular phylogenetic trees strongly supported the monophyly of Sect. Viola, Sect. Diffusae, Sect. Bilobatae and Sect. Vaginatae. The close sister relationship among Subgen. Melanium, Sect. Viola and Sect. Trigonocarpae was revealed, however, the clade of Sect. Trigonocarpae got low support. Subgen. Dischidium was confirmed to have a very close relationship with Subgen. Chamaemelanium by maximum parsimony tree, but the two Sections (Sect. Longicalcaratae and Sect. Brevicalcaratae) under Subgen. Dischidium should be combined together. Phylogenetic trees also showed that Pinnatae should be treated as a subsection under Sect. Adnatae. Besides, the systematic status of V. lucens, V. magnifica, V. dissecta and V. yunnanensis were discussed combining molecular results with morphologic characters.