Contrasted patterns of local adaptation to climate change across the range of an evergreen oak, Quercus aquifolioides

Long-lived tree species are genetically differentiated and locally adapted with respect to fitness-related traits, but the genetic basis of local adaptation remains largely unresolved. Recent advances in population genetics and landscape genomic analyses enable identification of putative adaptive loci and specific selective pressures acting on local adaptation. Here we sampled 60 evergreen oak (Quercus aquifolioides) populations throughout the species’ range and pool-sequenced 587 individuals at drought stress candidate genes. We analyzed patterns of genetic diversity and differentiation for 381 single nucleotide polymorphisms (SNPs) from 65 candidate genes and eight microsatellites. Outlier loci were identified by genetic differentiation analysis and genome–environment associations. The response pattern of genetic variation to environmental gradient was assessed by linear isolation by distance/environment tests, redundancy analysis and non-linear methods. SNPs and microsatellites revea...长寿树种在与适合度相关的性状上存在遗传分化并已发生本地适应，但本地适应的遗传基础在很大程度上仍未阐明。近年来，种群遗传学（population genetics）与景观基因组分析技术的进步，使得我们能够鉴定参与本地适应的潜在适应性位点与特异性选择压力。本研究在该物种的整个分布范围内，采样了60个常绿栎（Quercus aquifolioides）种群，并针对干旱胁迫候选基因对587个个体进行了混池测序。我们针对来自65个候选基因的381个单核苷酸多态性位点（single nucleotide polymorphisms, SNPs）以及8个微卫星（microsatellites）标记，分析了遗传多样性与遗传分化模式。通过遗传分化分析与基因组-环境关联分析，我们鉴定出了异常位点。我们通过线性距离隔离/环境隔离检验、冗余分析以及非线性方法，评估了遗传变异沿环境梯度的响应模式。单核苷酸多态性位点与微卫星标记的结果揭示……