Aim: Scots pine is one of the dominant tree species in forest ecosystems of the temperate and boreal zones in Eurasia. Since the Tertiary, it has persisted also in the Mediterranean region, forming relict populations. In this study, we investigate rangewide genetic diversity of Scots pine, aiming to provide comprehensive information on the phylogeography and genetic resources of the species.Location: Europe and Asia. Methods: Thirteen paternally inherited chloroplast microsatellite (cpSSR) loci were used to investigate the genetic structure of 62 populations from Fennoscandia and 30 populations from the Mediterranean. We also surveyed variability of two maternally inherited mitochondrial DNA (mtDNA) regions and additionally included literature data from 156 populations (248 populations in total).Results: Scots pine retains an overall high genetic diversity in the chloroplast genome but, unexpectedly, the historically younger populations from Fennoscandia showed statistically higher mean intrapopulation diversity than the Mediterranean stands (0.807 and 0.750, respectively). The latter also contained a lower number of private cpSSR haplotypes.Population differentiation with respect to mtDNA was higher (G ST = 0.628) than at cpSSR (G ST = 0.015) indicating an efficient pollen-mediated gene flow among refugial populations of the species. One novel haplotype mtDNA was found, increasing the number of known mitotypes for the species from 4 to 5. The geographic distribution of mitotypes was structured into four groups corresponding to the main refugial areas of the species. Main conclusions: Genetic impoverishment of the Mediterranean populations may enhance their vulnerability to future environmental changes. The spatial distribution of two mitotypes in Fennoscandia, featuring predominance of mitotype a in Norway and Sweden and mitotype b in Finland, gives strong support for dual colonization of that region from south-eastern (Finland) and south-western (Sweden) directions. These results thus provide new insights into both Holocene expansion of Scots pine and the present distribution of species' genetic resources. | 541 DERING Et al.

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In the present study, a genetic analysis of nuclear microsatellites was conducted in Abies cilicica populations growing in West Taurus, East Taurus, and Lebanon mountains to obtain evidence for significant genetic differentiation. Despite range fragmentation, all examined populations tended to maintain a relatively high level of genetic diversity (H E = 0.724) and showed moderate genetic differentiation (F ST = 0.134) that is frequently noted in Mediterranean tree species. However, significant inbreeding, bottleneck effect, and low effective population sizes were detected, that may negatively affect species genetic resources. Bayesian clustering revealed three distinct groups, "West Taurus", "East Taurus," and "Lebanon", which reflect geographic structure of the species natural range. Minor genetic admixture between Lebanese and East Taurus populations of A. cilicica was found, but no genetic admixture between Lebanese populations and West Taurus. We argue that significant genetic differentiation discovered among areas of species occurrence is probably due to the effect of long-lasting genetic isolation that started in that region along with the Pleistocene climatic alternation and was further enhanced with human-induced deforestations.