A Phylogenetic study of Chinese Polygonatum (Polygonateae, Asparagaceae)
13 November 2018Zhao, Lihua; Zhou, Songdong; He, Xingjin
Polygonatum Mill., consists of about more than 60 species, which are mainly distributed in East Asia, especially China and Japan, has received considerable attention from plant taxonomists. Nevertheless, there are still many gaps in our knowledge of this genus, especially of those species endemic to China that have often not been included in previous studies. We re-evaluate the taxonomy of 28 Chinese Polygonatum species with emphasis on molecular evidence. Phylogenetic analyses were carried out on sequence data of four plastid DNA regions: atpB-rbcL, matK, rbcL and rps16, using maximum parsimony and Bayesian approaches to evaluate species relationships. Analyses of combined datasets of the four regions revealed the following results: (i) Chinese Polygonatum was monophyletic at the current level of sampling; (ii) three major lineages in Polygonatum were well supported, largely correlated with cytological and morphological charactres; (ⅲ) Our results, along with the results of previous works support that P. simizui should be a synonym of P. odoratum; and (ⅳ) Polygonatum cirrhifoliodes is shown to be distinct from P. cirrhifolium.