Divergent Selection and Local Adaptation in Disjunct Populations of an Endangered Conifer, Keteleeria davidiana var. formosana (Pinaceae)

Abstract

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.

Signatures of selection in mammalian clock genes with coding trinucleotide repeats: Implications for studying the genomics of high‐pace adaptation

“…In the recent past, there has been an advancement in empirical studies implicating climatic and environmental gradients in the generation and maintenance of adaptive genetic diversity through selection, even in the face of ongoing gene flow between populations (DeFaveri et al., 2013; Fang et al., 2013; Watanabe, Kazama, Omura, & Monaghan, 2014). Clock genes in particular have been demonstrated to be important targets of selection, as they are likely to provide a means by which species can adapt to seasonal changes or adjust to novel environments (Kondratova et al., 2010).…”

Assessment of Genetic Diversity and Population Structure in a Global Reference Collection of 531 Accessions of Carthamus tinctorius L. (Safflower) Using AFLP Markers

“…BAPS analysis was initially performed at K=4 using the ΔK value obtained by STRUCTURE as described in earlier studies (Fang et al 2013). BAPS analysis at K=4 was done with five replications, and the results were compared with those obtained using STRUCTURE analysis (Fig.…”

Evidences of local adaptation in quantitative traits in Prosopis alba (Leguminosae)

“…Attempts to identify, understand, and detect selection pressures for local adaptation are vigorous areas for research willing to detect potential for evolutionary responses to environmental changes, in particular in tree populations (Leimu and Fisher 2008;Fang et al 2013;Sork et al 2013). The study of a provenance trials results critical to assess the relative contribution of genetic and environmental factors on adaptively and economically important traits under a common garden; this information is crucial because the response in any management program is based in the additive genetic variance component and the selection pressure that is going to be applied.…”