Genomic insights into adaptation to heterogeneous environments for the ancient relictual Circaeaster agrestis (Circaeasteraceae, Ranunculales).
Genomic insights into adaptation to heterogeneous environments for the ancient relictual Circaeaster agrestis (Circaeasteraceae, Ranunculales).
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DOI：
10.1111/nph.16669
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Xu Zhang;Yanxia Sun;J. Landis;Jian-Wen Zhang;Linsen Yang;Nan Lin;Huajie Zhang;R. Guo;
中科院分区：
文献类型：
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作者：
Xu Zhang;Yanxia Sun;J. Landis;Jian-Wen Zhang;Linsen Yang;Nan Lin;Huajie Zhang;R. Guo;
研究环境异质性与局部适应之间的相互作用对于了解物种的进化历史至关重要，为研究生物体对气候快速变化的响应提供前提。然而，对于大多数物种来说，空间异质性究竟如何促进种群分化以及基因组变异如何促进适应性进化仍然知之甚少。我们利用 RAD-seq 和质体组数据研究了地理和环境变量对高山遗迹草本植物 Circaeaster agrestis 种群分化的贡献，以及当地适应的遗传基础。我们检测到显着的遗传结构，区域间遗传多样性异常不平衡，以及距离隔离和抗性隔离的信号。据估计，这些种群在中新世晚期开始出现分化，同时祖先也可能分布在横断山脉和邻近地区。环境梯度和冗余分析都揭示了遗传变异和温度变量之间的显着关联。基因组-环境关联分析确定了 16 个假定的适应性基因座，主要与生物和非生物胁迫抗性相关。我们的全基因组数据为了解环境异质性在塑造遗传结构中的重要作用提供了新的见解，并获取了古代孑遗物种局部适应的足迹，为未来的保护工作提供了信息。
Investigating the interaction between environmental heterogeneity and local adaptation is critical to understand the evolutionary history of a species, providing the premise for studying the response of organisms to rapid climate change. However, for most species how exactly the spatial heterogeneity promotes population divergence and how genomic variations contribute to adaptive evolution remain poorly understood. We examine the contributions of geographical and environmental variables to population divergence of the relictual, alpine herb Circaeaster agrestis, as well as genetic basis of local adaptation using RAD-seq and plastome data. We detected significant genetic structure with an extraordinary disequilibrium of genetic diversity among regions, and signals of isolation-by-distance along with isolation-by-resistance. The populations were estimated to begin diverging in the late Miocene, along with a possible ancestral distribution of the Hengduan Mountains and adjacent regions. Both environmental gradient and redundancy analyses revealed significant association between genetic variation and temperature variables. Genome-environment association analyses identified 16 putatively adaptive loci mainly related to biotic and abiotic stress resistance. Our genome wide data provide new insights into the important role of environmental heterogeneity in shaping genetic structure, and access the footprints of local adaptation in an ancient relictual species, informing future conservation efforts.