AUTHOR=Lin Yingyu , Yao Gang , Huang Chunxiu , Chao Zhi , Tian Enwei 

TITLE=Molecular evidence provides new insights into the evolutionary origin of an ancient traditional Chinese medicine, the domesticated “Baizhi”

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1388586

DOI=10.3389/fpls.2024.1388586

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>“Baizhi” is a famous herbal medicine in China, and it includes four landraces named as ‘Hangbaizhi’, ‘Chuanbaizhi’, ‘Qibaizhi’, and ‘Yubaizhi’. Long-term artificial selection had caused serious degradation of these germplasms. Determining the wild progenitor of the landraces would be benefit for their breed improvements. Previous studies have suggested <italic>Angelica dahurica</italic> var. <italic>dahurica</italic>, <italic>A. dahurica</italic> var. <italic>formosana</italic>, or <italic>A. porphyrocaulis</italic> as potential candidates, but the conclusion remains uncertain, and their phylogenetic relationships are still in controversy.</p></sec><sec><title>Methods</title><p>In this study, the genetic variation and phylogenetic analyses of these species and four landraces were conducted on the basis of both the nrITS and plastome datasets.</p></sec><sec><title>Results</title><p>Genetic variation analysis showed that all 8 population of four landraces shared only one ITS haplotype, meanwhile extremely low variation occurred within 6 population at plastid genome level. Both datasets supported the four landraces might be originated from a single wild germplasm. Phylogenetic analyses with both datasets revealed largely consistent topology using Bayesian inference and Maximum likelihood methods. Samples of the four landraces and all wild <italic>A. dahurica</italic> var. <italic>dahurica</italic> formed a highly supported monophyletic clade, and then sister to the monophyly clade comprised by samples of <italic>A. porphyrocaulis</italic>, while four landraces were clustered into one clade, which further clustered with a mixed branches of <italic>A. porphyrocaulis</italic> and <italic>A. dahurica</italic> var. <italic>dahurica</italic> to form sister branches for plastid genomes. Furthermore, the monophyletic <italic>A. dahurica</italic> var. <italic>formosana</italic> was far distant from the <italic>A. dahurica</italic> var. <italic>dahurica</italic>-“Baizhi” clade in <italic>Angelica</italic> phylogeny. Such inferences was also supported by the evolutionary patterns of nrITS haplotype network and K2P genetic distances. The outcomes indicated <italic>A. dahurica</italic> var. <italic>dahurica</italic> is most likely the original plant of “Baizhi”.</p></sec><sec><title>Discussion</title><p>Considering of phylogenetic inference and evolutionary history, the species-level status of <italic>A. dahurica</italic> var. <italic>formosana</italic> should be accepted, and the taxonomic level and phylgenetic position of <italic>A. porphyrocaulis</italic> should be further confirmed. This study preliminarily determined the wild progenitor of “Baizhi” and clarified the phylogenetic relationships among <italic>A. dahurica</italic> var. <italic>dahurica</italic>, <italic>A. dahurica</italic> var. <italic>formosana</italic> and <italic>A. porphyrocaulis</italic>, which will provide scientific guidance for wild resources protections and improvement of “Baizhi”.</p></sec>