Plant Conservation and Population Biology, Department of Biology, University of Leuven, Kasteelpark Arenberg 31, Heverlee, B-3001, Belgium.
Mol Ecol. 2014 Oct;23(19):4709-21. doi: 10.1111/mec.12813. Epub 2014 Jun 28.
The adaptive potential of tree species to cope with climate change has important ecological and economic implications. Many temperate tree species experience a wide range of environmental conditions, suggesting high adaptability to new environmental conditions. We investigated adaptation to regional climate in the drought-sensitive tree species Alnus glutinosa (Black alder), using a complementary approach that integrates genomic, phenotypic and landscape data. A total of 24 European populations were studied in a common garden and through landscape genomic approaches. Genotyping-by-sequencing was used to identify SNPs across the genome, resulting in 1990 SNPs. Although a relatively low percentage of putative adaptive SNPs was detected (2.86% outlier SNPs), we observed clear associations among outlier allele frequencies, temperature and plant traits. In line with the typical drought avoiding nature of A. glutinosa, leaf size varied according to a temperature gradient and significant associations with multiple outlier loci were observed, corroborating the ecological relevance of the observed outlier SNPs. Moreover, the lack of isolation by distance, the very low genetic differentiation among populations and the high intrapopulation genetic variation all support the notion that high gene exchange combined with strong environmental selection promotes adaptation to environmental cues.
树种适应气候变化的能力具有重要的生态和经济意义。许多温带树种经历了广泛的环境条件，这表明它们对新的环境条件具有很高的适应性。我们使用整合基因组、表型和景观数据的互补方法，研究了干旱敏感树种桤木（黑桤木）对区域气候的适应。在一个共同的花园和通过景观基因组学方法研究了总共 24 个欧洲种群。我们使用测序的基因型来鉴定全基因组的 SNP，结果产生了 1990 个 SNP。尽管检测到的适应性 SNP 的比例相对较低（2.86%的异常 SNP），但我们观察到异常等位基因频率、温度和植物性状之间存在明显的关联。与桤木典型的耐旱特性一致，叶片大小随温度梯度而变化，并且与多个异常位点存在显著关联，这证实了观察到的异常 SNP 的生态相关性。此外，缺乏距离隔离、种群间极低的遗传分化以及高种群内遗传变异都支持这样一种观点，即高基因交换与强烈的环境选择相结合促进了对环境线索的适应。
