Genetic diversity among Salvia miltiorrhiza Bunge and related species inferred from nrDNA ITS sequences

To investigate the genetic diversity and phylogenetic relationships of Salvia miltiorrhiza and related species, we analyzed the nuclear ribosomal DNA internal transcribed spacer (ITS) region for 7 accessions of Salvia miltiorrhiza and another 23 samples from other taxa within the genus Salvia by maximum parsimony and Bayesian inference analyses. There were 257 variation sites amounting to 40.8% of the total base pairs. All of the data revealed abundant genetic diversity in the genus Salvia. The results showed that the tested materials could be grouped into 3 clusters, and the 3 different occasions in Salvia were clustered into 1 clade, which suggests that the species from different occasions form independent lineages. We can easily distinguish S. miltiorrhiza from a variety of Salvia species in this manner. Moreover, according to cluster analysis, S. bowleyana, S. yunnanensis, and S. cavaleriei var. simplelefolia are good or potential germplasm resources for S. miltiorrhiza.