Chloroplast phylogeography ofIris dichotoma(Iridaceae), a widespread herbaceous species in East Asia

Abstract

Listen

Translate article

Both a complex topography and climate change have huge impacts on the distribution and genetic structure of extant species. Due to the lack of relevant molecular research, little is definitively known about the phylogeography of herbaceous plants in East Asia. Here we investigate the genetic diversity, population structure and historical population dynamics ofIris dichotomaPallas, a widespread perennial herbaceous species in northeastern and northern China. Twenty‐nine populations, totalling 297 individuals, were sampled throughout the Chinese distributional range ofI. dichotoma. The combined sequences of six chloroplast DNA fragments (petA‐psbE,rps18‐clpp,psbJ‐petA,trnD‐trnT,rps16andndhA) were used to identify 13 haplotypes, of which six were private ones restricted in a single population. Genetic differentiation amongI. dichotomapopulations, enabled us to infer potential refugia during the glacial period in the Yinshan Mountains–Yanshan Mountains, where high levels of haplotype and nucleotide diversity were detected. The results of a neutral test and mismatch distribution analysis both indicated thatI. dichotomaunderwent a recent population expansion. In East Asia, postglacial environmental and climatic changes appear to have promoted genetic diversification not only in better‐studied woody species, but also in herbaceous ones likeI. dichotoma. Future studies of more herbaceous plant species are needed to obtain better insight into how modern temperate biodiversity has developed in East Asia.