[Analysis of ITS sequences of some medicinal plants and their related species in Salvia].

Molecular systematic techniques were applied to reveal the genetic diversity of medicinal plants and their related species in Salvia. The internal transcribed spacer (ITS) as well as 5.8S rDNA sequences of 27 samples of Salvia were amplified using PCR method and sequenced. Mega 3.1 was used to analyze the genetic diversity within genus. The complete sequences of ITS plus 5.8S rDNA are about 612-617 bp. A phylogenetic tree generated by Neighbor-Joining method partly supported the morphological classification within Salvia, but incompatible results were also obtained in the treatment of phylogenetic positions of some species such as Salvia trijuga, Salvia flava var. flava and Salvia flava var. megalentha. The ITS regions of present Salria species showed considerable variation between subgenera in contrast with the conservative 5.8S rDNA sequences. The native Salvia species might have a different origin from the foreign species. The phylogenetic positions of subgenera and sections inferred by ITS analysis were comparable with that of traditional classification, while the phylogeny within sections is still doubtful due to limited information in ITS sequence and need to be further proved by other evidence. ITS analysis in this study supports the rationality of using species from Drymosphace section as substitute drug resources of Dan shen, but also reveals significant genetic differences between high mountain Dan shen species such as Salvia przewalskii with traditional Dan shen origins.