Genetic imprints and environment effects in a common garden of 500 Picea abies families from 160 sites throughout the Alps

Norway spruce is one of the economically and ecologically most important tree species in the Alps as well as in Europe. Given current climate change scenarios, a full understanding of the function of complex traits and their genetic base appears to be the only way to cope with effects that may be a menace to the performance and the survival of this species. In 2013 we established a common garden nearby Trento, Italy, using seeds from a mapping population constituted by the half-sib progeny of 518 families from 160 sites in the Alps. The phenotypic traits assessed were: germination time, bud-set, budburst, height and biomass parameters. Preliminary results show significant differences in germination and bud-set, and Northern families generally grew more in the common garden conditions than Southern ones. Parallel to the phenotypic assessment, genotyping was carried out on needle samples from the mother trees, and a candidate gene-based approach was used to search for association between single-nucleotide polymorphisms (SNP) detected in genes putatively involved in the control of the measured adaptive traits and the observed phenotypic variation. The discovery of polymorphisms underlying adaptive phenotypic traits is a fundamental goal of molecular genetics. Elucidation of the genetic components for ecologically relevant traits through association mapping at markers in candidate genes has been achieved for a variety of adaptive phenotypes in other tree species, and it has important applications ranging from marker assisted breeding to gene conservation in the face of climate change