Direct and correlated responses to artificial selection for growth and water?use efficiency in a Mediterranean pine

PREMISE Persistence of tree populations in the face global change relies on their capacity to respond biotic and abiotic stressors through plastic or adaptive changes. Genetic adaptation will depend additive genetic variation within heritability traits related stress tolerance. Because can be genetically linked, selective pressure acting one trait may lead correlated responses other traits. METHODS To test direct selection for growth drought tolerance Pinus halepensis, we selected trees a parental population higher greater water-use efficiency (WUE) compared offspring with random from two contrasting common gardens. We estimated WUE stressors. RESULTS found strong response high realized WUE, but no growth. Correlated life-history were not significant, except concentration some chemical defenses, which was mother than unselected control trees. CONCLUSIONS The empirical evidence suggests that P. halepensis has potential evolve increasing stress. Contrary expectations, results are conclusive negative impact key