Data from: Trait variation in response to varying winter temperatures, diversity patterns and signatures of selection along the latitudinal distribution of the widespread grassland plant Arrhenatherum elatius

Across Europe, genetic diversity can be expected to decline toward the
North because of stochastic and selective effects which may imply
diminished phenotypic variation and less potential for future genetic
adaptations to environmental change. Understanding such latitudinal
patterns can aid provenance selection for breeding or assisted migration
approaches. In an experiment simulating different winter temperatures, we
assessed quantitative trait variation, genetic diversity, and
differentiation for natural populations of the grass Arrhenatherum elatius
originating from a large latitudinal gradient. In general, populations
from the North grew smaller and had a lower flowering probability. Toward
the North, the absolute plastic response to the different winter
conditions as well as heritability for biomass production significantly
declined. Genetic differentiation in plant height and probability of
flowering were very strong and significantly higher than under neutral
expectations derived from SNP data, suggesting adaptive differentiation.
Differentiation in biomass production did not exceed but mirrored patterns
for neutral genetic differentiation, suggesting that migration-related
processes caused the observed clinal trait variation. Our results
demonstrate that genetic diversity and trait differentiation patterns for
A. elatius along a latitudinal gradient are likely shaped by both local
selection and genetic drift.