AUTHOR=Xiong Yi , Xiong Yanli , Shu Xin , Yu Qingqing , Lei Xiong , Li Daxu , Yan Jiajun , Bai Shiqie , Ma Xiao 

TITLE=Molecular Phylogeography and Intraspecific Divergences in Siberian Wildrye (Elymus sibiricus L.) Wild Populations in China, Inferred From Chloroplast DNA Sequence and cpSSR Markers

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.862759

DOI=10.3389/fpls.2022.862759

ISSN=1664-462X

ABSTRACT=<p>A detailed understanding of the distribution and degree of genetic variation within a species is important for determining their evolutionary potential, which in return facilitates the development of efficient conservation strategies aimed at preserving adaptive genetic variation. As an important perennial, cool-season grass in temperate Eurasia, increasing attention has been paid to Siberian wildrye (<italic>Elymus sibiricus</italic>) due to its excellent ecological utilization value and forage production potential in China, particularly in the Qinghai–Tibet Plateau (QTP) regions. In this study, we applied two chloroplast (cp) genes (<italic>matK</italic> and <italic>rbcL</italic>), three cp spacer regions (<italic>trnY</italic>-<italic>GUA</italic>∼<italic>trnD</italic>-<italic>GUC</italic>, <italic>atpH</italic>∼<italic>atpF</italic>, and <italic>rps4</italic>∼<italic>trnT</italic>-<italic>UGU</italic>), and six cpSSR markers to the genetic and phylogenetic analysis of 137 wild <italic>E. sibiricus</italic> accessions from 23 natural populations that represent the main distribution regions in China. The results show the highest genetic diversity (<italic>h</italic> = 0.913) and haplotype richness (10 haplotypes) for the QTP population, which indicates QTP as the probable diversity center and geographic origin of <italic>E. sibiricus</italic> in China. Population divergence was high, indicating a significant phylogeographic structure together with a significantly higher N<sub>st</sub> value (N<sub>st</sub> &gt; G<sub>st</sub>, <italic>P</italic> &lt; 0.05) at the species level, QTP+XJ (combined populations from QTP and Xinjiang), QTP+NC (combined populations from QTP and North China), and XJ+NC (combined populations from Xinjiang and North China) group levels, respectively. An expansion was revealed in the distributional range of <italic>E. sibiricus</italic> in China from paleo times up to the recent past, while a dramatic range of contraction was predicted for the near future. The predicted main limiting factor for the further spread of <italic>E. sibiricus</italic> is an increasing global mean temperature. We recommend that the combination of Es-cpDNA1 and Es-cpDNA3+4+5 can be used as effective markers for phylogenetic analysis and phylogeographical history analysis of <italic>E. sibiricus</italic>. These findings shed new light on the historical population dynamics of cold-season herbs in the QTP region and the north of China and are of great significance for the future establishment of protection and collection strategies for wild <italic>E. sibiricus</italic> germplasm.</p>