Data from: Genetic basis of local adaptation and flowering time variation in Arabidopsis lyrata

Understanding how genetic variation at individual loci contributes to
adaptation of populations to different local environments is an important
topic in modern evolutionary biology. To date, most evidence has pointed
to conditionally neutral quantitative trait loci (QTL) showing fitness
effects only in some environments, while there has been less evidence for
single-locus fitness trade-offs. At QTL underlying local adaptation,
alleles from the local population are expected to show a fitness
advantage. Cytoplasmic genomes also can have a role in local adaptation,
but the role of cytonuclear interactions in adaptive differentiation has
remained largely unknown. We mapped genomic regions underlying adaptive
differentiation in multiple fitness components and flowering time in
diverged populations of a perennial plant Arabidopsis lyrata. Experimental
hybrids for this purpose were grown in natural field conditions of the
parental populations in Norway and North Carolina (NC), USA and in the
greenhouse. We found QTL where high fitness and early flowering were
associated with local alleles, indicating a role of different selection
pressures in phenotypic differentiation. At two QTL regions, a fitness
component showing local adaptation between the parental populations also
showed signs of putative fitness trade-offs. Beneficial dominance effects
of conditionally neutral QTL for different fitness components resulted in
hybrid vigor at the Norwegian site in the F2 hybrids. We also found that
cytoplasmic genomes contributed to local adaptation and hybrid vigor by
interacting with nuclear QTL, but these interactions did not show evidence
for cytonuclear coadaptation (high fitness of local alleles combined with
the local cytoplasm).