AUTHOR=Wang Xin , Liu Xiao-Quang , Ko Ya-Zhu , Jin Xiao-Lei , Sun Jia-Hui , Zhao Zhen-Yu , Yuan Qing-Jun , Chiang Yu-Chung , Huang Lu-Qi 

TITLE=Genetic Diversity and Phylogeography of the Important Medical Herb, Cultivated Huang-Lian Populations, and the Wild Relatives Coptis Species in China

JOURNAL=Frontiers in Genetics

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2020.00708

DOI=10.3389/fgene.2020.00708

ISSN=1664-8021

ABSTRACT=<p>Huang-lian (<italic>Coptis</italic> plants in China) are essential medicinal plants in China, <italic>C. chinensis</italic> var. <italic>chinensis</italic> and <italic>C. deltoidea</italic> have been domesticated and cultivated for 700 years. In this study, the genetic diversity patterns and biogeographical information of cultivated Huang-lian and their wild relatives <italic>Coptis</italic> species were assessed using three plastids DNA regions. A total of 186 individuals from twenty-seven populations representing two species of cultivated Huang-lian and four species of wild relatives were collected and analyzed. Twenty-four haplotypes of six species were identified when three plastid spacers were combined. Historical biogeography inference revealed multiple dispersal events in the groups of cultivated Huang-lian and <italic>C. omeiensis</italic>. This evidence can infer that large initial population size and interbreeding with co-existing wild relatives in expanding new planting areas might be the main reason for maintaining the high genetic diversity of cultivated Huang-lian. Nevertheless, the multimodal curve of mismatch analysis and positive or negative differed among species and populations by neutrality tests indicated some groups of cultivated Huang-lian experienced genetic bottlenecks. Phylogeny analysis (NJ, MP, BI) showed that cultivated Huang-lian and <italic>C. omeiensis</italic> were clustered into a monophyletic group while <italic>C. chinensis</italic> var. <italic>brevisepala</italic> was paraphyletic, having earlier divergence time from <italic>C. chinensis</italic> var. <italic>chinensis</italic> (7.6 Ma) than <italic>C. omeiensis.</italic> Parsimony network demonstrated that <italic>C. deltoidea</italic> had more shared haplotypes with <italic>C. omeiensis</italic> than <italic>C. chinensis</italic> var. <italic>chinensis</italic>, and other haplotypes of <italic>C. deltoidea</italic> and <italic>C. omeiensis</italic> had less mutation steps than that of <italic>C. chinensis</italic> var. <italic>chinensis</italic> and <italic>C. omeiensis.</italic> This evidence suggests that <italic>C. omeiensis</italic> has a closer relationship with cultivated Huang-lian and might be a potential wild relative to <italic>C. deltoidea</italic>. The results reported here provide the baseline data for preserving genetic resources of Huang-lian and also evaluating the genetic impacts of long-term cultivation on medicinal plants, which could be instructive to future cultivation projects of traditional Chinese medicinal plants.</p>