Phenotypic landscapes: phenological patterns in wild and cultivated barley

Phenotypic variation in natural populations is the outcome of the joint effects of environmentally induced adaptations and neutral processes on the genetic architecture of quantitative traits. In this study we examined the role of adaptation in shaping wild barley phenotypic variation along different environmental gradients. Detailed phenotyping of 164 wild barley (Hordeum spontaneum) accessions from Israel (of the Barley1K collection), and 18 cultivated barley (H. vulgare) varieties, was conducted in common garden field trials. Cluster analysis based on phenotypic data indicated that wild barley in this region can be differentiated into three ecotypes in accordance with their ecogeographic distribution: north, coast, and desert. Population differentiation (Qst) for each trait was estimated using a hierarchical Bayesian model and compared to neutral differentiation (Fst) based on 42 microsatellite markers. This analysis indicated that the three clusters diverged in morphological but not...