Molecular analysis of Leonurus species in China based on ITS and matK sequences.

The genus Leonurus has long been recognized as a natural group, but its interspecific relationship has not yet been studied in the light of sequence data. The ITS regions and matK sequences of all subgenera of Leonurus in China were amplified, sequenced and investigated. Phylogenies generated by maximum parsimony and neighbor-joining methods and division of the genus into two major clades. The phylogenetic results indicated that L. chaituroides has the very close phylogenetic relationship with Subg. Cardiochilium and supported the notion that L. macranthus acts as the bridge between Subg. cardiochilium and Subg. Leonurus. According to the analysis of information given by ITS and matK sequences, we suggest that ITS sequences would be more suitable to serve as markers for authentication of Herba Leonuri than matK does.