Genomic clines across the species boundary between a hybrid pine and its progenitor in the eastern Tibetan Plateau  

作　　者：Jing-Fang Guo Wei Zhao Bea Andersson Jian-Feng Mao Xiao-Ru Wang 

机构地区：[1]National Engineering Research Center of Tree Breeding and Ecological Restoration,State Key Laboratory of Tree Genetics and Breeding,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants,Ministry of Education,College of Biological Sciences and Technology,Beijing Forestry University,Beijing 100083,China [2]Department of Ecology and Environmental Science,UmeåPlant Science Centre,UmeåUniversity,90187 Umeå,Sweden

出　　处：《Plant Communications》2023年第4期240-254,共15页植物通讯（英文）

基　　金：supported by grants from the Swedish Research Council(VR 2017-04686);T4F program,Sweden.

摘　　要：Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa and their progenitors are,however,less clearly defined.This study investigated the genetic structure and clines in Pinus densata,a pine of hybrid origin on the southeastern Tibetan Plateau,to gain an understanding of the contemporary dynamics of species barriers.We analyzed genetic diversity in a range-wide collection of P.densata and representative populations of its progenitors,Pinus tabuliformis and Pinus yunnanensis,using exome capture sequencing.We detected four distinct genetic groups within P.densata that reflect its migration history and major gene-flow barriers across the landscape.The demographies of these genetic groups in the Pleistocene were associated with regional glaciation histories.Interestingly,population sizes rebounded rapidly during interglacial periods,suggesting persistence and resilience of the species during the Quaternary ice age.In the contact zone between P.densata and P.yunnanensis,3.36%of the analyzed loci(57849)showed exceptional patterns of introgression,suggesting their potential roles in either adaptive introgression or reproductive isolation.These outliers showed strong clines along critical climate gradients and enrichment in a number of biological processes relevant to high-altitude adaptation.This indicates that ecological selection played an important role in generating genomic heterogeneity and a genetic barrier across a zone of species transition.Our study highlights the forces that operate to maintain species boundaries and promote speciation in the Qinghai-Tibetan Plateau and other mountain systems.

关 键 词：ecological selection demographic history genomic cline introgression outliers reproductive isolation species boundary 

分 类 号：Q94[生物学—植物学]