12 nuclear microsatellite loci scores for 543 adult trees of Tilia cordata in Lithuainia

<p>Genetic signature of the natural genepool of <i>Tilia cordata</i> Mill. in Lithuania: compound evolutionary and anthropogenic effects</p> <p><i>Tilia cordata</i> Mill. is a valuable tree species enriching the ecological values of the coniferous dominated boreal forests in Europe. Following the historical decline, spreading of <i>Tilia</i> sp. is challenged by the elevated inbreeding and habitat fragmentation. We studied the geographical distribution of genetic diversity of <i>Tilia cordata</i> populations in Lithuania. We used 14 genomic microsatellite markers to genotype 543 individuals from 23 wild growing populations. We found that <i>Tilia cordata</i> retained high levels of genetic diversity (population F_is = 0 to 0.15, H_o= 0.53 to 0.69, H_e= 0.56 to 0.75). AMOVA, Bayesian clustering and Monmonier's barrier detection indicate weak but significant differentiation among the populations (F_st = 0.037***) into geographically interpretable clusters of (a) western Lithuania with high genetic heterogeneity but low genetic diversity, bottleneck effects, (b) relatively higher genetic diversity of <i>Tilia cordata</i> on rich and most soils of midland lowland, and (c) the most differentiated populations on poor soils of the coolest north-eastern highland possessing the highest rare allele frequency but elevated inbreeding and bottleneck effects. Weak genetic differentiation among the <i>Tilia cordata</i> populations in Lithuania implies common ancestry, absence of strong adaptive gradients and effective genetic exchange possible mediated via the riparian networks. A hypothesis on riparian networks as geneflow mediators in <i>Tilia cordata</i> was raised based on results of this study.</p>