Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
PLoS One. 2013 Jul 22;8(7):e70162. doi: 10.1371/journal.pone.0070162. Print 2013.
The present study investigated the genetic diversity, population structure, F ST outliers, and extent and pattern of linkage disequilibrium in five populations of Keteleeria davidiana var. formosana, which is listed as a critically endangered species by the Council of Agriculture, Taiwan. Twelve amplified fragment length polymorphism primer pairs generated a total of 465 markers, of which 83.74% on average were polymorphic across populations, with a mean Nei's genetic diversity of 0.233 and a low level of genetic differentiation (approximately 6%) based on the total dataset. Linkage disequilibrium and HICKORY analyses suggested recent population bottlenecks and inbreeding in K. davidiana var. formosana. Both STRUCTURE and BAPS observed extensive admixture of individual genotypes among populations based on the total dataset in various clustering scenarios, which probably resulted from incomplete lineage sorting of ancestral variation rather than a high rate of recent gene flow. Our results based on outlier analysis revealed generally high levels of genetic differentiation and suggest that divergent selection arising from environmental variation has been driven by differences in temperature, precipitation, and humidity. Identification of ecologically associated outliers among environmentally disparate populations further support divergent selection and potential local adaptation.
本研究调查了台湾农业委员会将其列为极度濒危物种的台湾油杉 5 个种群的遗传多样性、种群结构、FST 异常值、连锁不平衡程度和模式。12 对扩增片段长度多态性引物共产生了 465 个标记，平均 83.74%在种群间具有多态性，基于总数据集的平均 Nei 遗传多样性为 0.233，遗传分化程度较低（约 6%）。连锁不平衡和 HICKORY 分析表明，台湾油杉近期发生了种群瓶颈和近交。基于总数据集，STRUCTURE 和 BAPS 在各种聚类场景中均观察到种群间个体基因型的广泛混合，这可能是由于祖先变异的不完全谱系分选而不是近期基因流的高速度所致。我们基于异常值分析的结果表明遗传分化水平普遍较高，表明环境变化引起的分歧选择是由温度、降水和湿度的差异驱动的。在环境差异较大的种群中识别出与生态相关的异常值进一步支持了分歧选择和潜在的局部适应。
