Data from: Genetic and epigenetic differentiation between natural Betula ermanii (Betulaceae) populations inhabiting contrasting habitats

Disentangling the molecular mechanisms of adaptation in natural plant populations in response to different environmental conditions is a central topic in evolutionary biology. In the present study, we investigated a wind-pollinated woody species of Changbai Mountain of northeastern China, namely, Betula ermanii Cham. This woody species B. ermanii is not only a dominant species in subalpine forest (SF), but it also occurs in the alpine tundra (AT) regions. This attribute indicates that it may play important roles in the two contrast habitats. In order to evaluate the influences of different habitats on differentiation in B. ermanii, we assessed the genetic and epigenetic population structure in selected populations from two contrasting habitats by using amplified fragment length polymorphism (AFLP) and methylation-sensitive AFLP techniques. According to our results, the AT group not only exhibits higher genetic and epigenetic diversity than the SF group but also shows greater population genetic and epigenetic differentiation. In addition, the analysis of cytosine methylation levels also revealed that the AT group exhibits higher degrees of genome methylation than the SF group. Taken together, our results indicate that populations from two contrasting habitats show significantly different genetic and epigenetic population structures. Along with other potential explanations, these findings suggest that environmental conditions could play an important role in facilitating adaptive evolution in B. ermanii.解析自然植物种群响应不同环境条件的适应性分子机制，是进化生物学领域的核心研究议题。本研究以中国东北长白山的风媒木本植物——岳桦（Betula ermanii Cham.）为研究对象。该木本物种不仅是亚高山森林（subalpine forest, SF）的优势物种，同时也分布于高山苔原（alpine tundra, AT）区域，这一分布特征表明其在两类截然不同的生境中均可能发挥关键生态功能。为探究不同生境对岳桦种群分化的影响，本研究采用扩增片段长度多态性（amplified fragment length polymorphism, AFLP）与甲基化敏感扩增片段长度多态性（methylation-sensitive AFLP）技术，对两类生境中的采样种群开展了遗传与表观遗传种群结构分析。研究结果显示，高山苔原组（AT组）的遗传与表观遗传多样性均高于亚高山森林组（SF组），且种群遗传与表观遗传分化程度也更为显著。此外，胞嘧啶甲基化水平分析表明，AT组的基因组甲基化程度同样高于SF组。综上，本研究结果证实，两类不同生境中的岳桦种群具有显著分化的遗传与表观遗传种群结构。结合其他潜在解释机制，本研究发现提示，环境条件在岳桦的适应性进化过程中发挥了重要的推动作用。