Across two phylogeographic breaks: Quaternary evolutionary history of a mountain aspen (Populus rotundifolia) in the Hengduan Mountains  

作　　者：Jieshi Tang Xiaoyan Fan Richard I.Milne Heng Yang Wenjing Tao Xinran Zhang Mengyun Guo Jialiang Li Kangshan Mao 

机构地区：[1]Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education,College of Life Sciences,State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,PR China [2]Institute of Molecular Plant Sciences,University of Edinburgh,Edinburgh EH93JH,UK [3]School of Ecology and Environment,Tibet University,Lhasa 850000,PR China

出　　处：《Plant Diversity》2024年第3期321-332,共12页植物多样性（英文版）

基　　金：funded by the National Natural Science Foundation of China(grants 41571054 and 31622015);the National Basic Research Program of China(grant 2014CB954100);Sichuan University(Fundamental Research Funds for the Central Universities,SCU2021D006 and SCU2022D003;Institutional Research Funds,2021SCUNL102).

摘　　要：Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.

关 键 词：Chloroplast DNA MICROSATELLITE Phylogeographic break Populus rotundifolia Quaternary history Wind direction 

分 类 号：Q948[生物学—植物学]