Data from: Adaptive differentiation coincides with local bioclimatic conditions along an elevational cline in populations of a lichen-forming fungus

Background: Many fungal species occur across a variety of habitats.
Particularly lichens, fungi forming symbioses with photosynthetic
partners, have evolved remarkable tolerances for environmental extremes.
Despite their ecological importance and ubiquity, little is known about
the genetic basis of adaption in lichen populations. Here we studied
patterns of genome-wide differentiation in the lichen-forming fungus
Lasallia pustulata along an altitudinal gradient in the Mediterranean
region. We resequenced six populations as pools and identified highly
differentiated genomic regions. We then detected gene-environment
correlations while controlling for shared population history and pooled
sequencing bias, and performed ecophysiological experiments to assess
fitness differences of individuals from different environments. Results:
We detected two strongly differentiated genetic clusters linked to
Mediterranean and temperate-oceanic climate, and an admixture zone, which
coincided with the transition between the two bioclimates. High altitude
individuals showed ecophysiological adaptations to wetter and more shaded
conditions. Highly differentiated genome regions contained a number of
genes associated with stress response, local environmental adaptation, and
sexual reproduction. Conclusions: Taken together our results provide
evidence for a complex interplay between demographic history and spatially
varying selection acting on a number of key biological processes,
suggesting a scenario of ecological speciation.