Journal of Systematics and Evolution

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  • 收稿日期:2019-12-22 接受日期:2020-11-03

Genomic signals reveal past evolutionary dynamics of Quercus schottkyana and its response to future climate change

Xiao-Long Jiang1, 2, Zhi-Hao Su3, Gang-Biao Xu2, Min Deng1, 4 #   

  1. 1Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, / Shanghai Chenshan Botanical Garden, Shanghai 201602, China
    2The Laboratory of Forestry Genetics, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
    3Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
    4School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, China
  • Received:2019-12-22 Accepted:2020-11-03

Abstract:

Understanding the past and future evolutionary dynamics of dominant species in a forest is important for guiding decisions for biodiversity conservation, forest management, and vegetation restoration. This study used Quercus schottkyana, a dominant tree in subtropical evergreen broad-leaved forests in southwest China, to investigate the influences of past environmental fluctuations and future changes in climate on the dynamics of tree demographics. Genomic data were obtained for 133 samples of Q. schottkyana from 22 populations using double-digest genotyping by sequencing. The SNPs in the genome showed a uniform distribution. Based on PCA and ADMIXTURE analysis, two distinct lineages and one mixed group were identified that corresponded to their geographical distribution. Approximate Bayesian Computation analyses provided evidence that the divergence among Q. schottkyana populations could be driven by the collision between the Asian and Indian plates during the Miocene, and that climatic fluctuations in the late Pleistocene led to the introgression. The analysis of genotype–environment relationships showed that annual precipitation and geographic distance were associated with spatial genetic variation. Populations of Q. schottkyana in the northern area of the Jinsha River basin were predicted to be the most vulnerable to future climate change. To increase genetic diversity in the northern Jinsha River basin and to buffer threats from future climate change, managers could use a mixture of local and alien seeds during forest restoration and management. This case study can promote further investigations into assessing how past and future climate change impacts genetic divergence and local adaptation of trees in forests.

Key words: climate change, demographic history, forest dynamics, genomic vulnerability, landscape genomics, Quercus