Natural variation in Aspen (Populus tremula): the Swedish Aspen Collection.

VIRGINIA LUQUEZ, DAVID HALL, BENEDICTE ALBRECTSEN, M. VICTORIA GARCÍA, PÄR INGVARSSON, STEFAN JANSSON.

Visegrád, Hungría.

Conferencia; Third EPSO Conference: Plant Dynamics: from molecules to ecosystems.; 2006

European Plant Science Organization

Natural variation in Aspen (Populus tremula): the Swedish Aspen Collection.   Virginia Luquez *, David Hall §, Benedicte Albrectsen*, M. Victoria García §,  Pär Ingvarsson§, Stefan Jansson*. * Umeå Plant Science Centre, Department of Plant Physiology, University of Umeå, SE-901 87, Umeå, Sweden. § Department of Ecology and Environmental Science, University of Umeå.   Aspen is currently established as the main model system for genetic, genomic and physiological research in trees. Swedish Aspen (Populus tremula) grows in different environments across Sweden showing phenotypic variation in different traits that is expected to reflect the genetic variation that is important for local adaptation. To analyze the natural phenotypic and genetic variation the Swedish Aspen Collection (SwAsp) was established. Trees were taken from 12 different populations across Sweden, from 56° to 66° NL and planted in two common gardens, and also kept in pots in the greenhouse. We have collected phenotypic data for e g growth, phenology, herbivory, pathogens etc. Some traits like bud set showed a strong clinal variation pattern along latitude, in both the field trials and the greenhouse. Leaf abscission and growth measurements displayed also clinal variation, but bud flush did not change along a latitudinal cline. We have also genotyped the collection using neutral markers and found that there is no population substructure. We have used association mapping to find mutations in the phyB2 gene that describes about 10 % of the variation in timing of bud set, and are also scoring other candidate genes for phenology.