Phylogeography of a herbal <i>Pinellia ternata</i> reveals repeated range expansions and inter/postglacial recolonization routes on the fragmented distribution pattern in China

Most plant phylogeographic studies in China have focused on the importance of genetic divergence and where should the shelter be located. Little attention has been paid to range expansion and recolonization routes in this region. In this study, two cpDNA fragments (<i>psb</i>K-<i>psb</i>I and <i>trn</i>L-F), two pairs of nuclear gene sequences (ITS and ETS), and nine pairs of SSR molecular markers were used, combined with Bayesian Skyline Plot method, gene barrier analysis, and species distribution models to explore the phylogeographical pattern, potential expansion routes and population dynamic history of <i>Pinellia ternata</i> from 22 population. The results showed that phylogeograhical pattern and genetic structure for <i>P. ternata</i> are effected by environmental heterogeneity and climate fluctuation, and it can be divided into two groups (Southwest group, Central and Eastern group) and thus there are at least two glacial refugia in China. Three expanding routes within groups were explored to contribute to the phylogeogrephic pattern of <i>P. ternata</i> based on the geographical distribution and network analysis of haplotypes. In a word, our study reveals repeated range expansions and inter/postglacial recolonization routes on the fragmented distribution pattern in China and resolves the refugia distributing in China and has also certain reference value for the protection of the medicinal plant <i>P. ternata</i>.