The Swedish Aspen Collection: a new resource to study natural genetic variation in Populus.

LUQUEZ VIRGINIA M.C.; HALL DAVID; ALBRECTSEN BENEDICTE; INGVARSSON PÄR; JANSSON STEFAN

Congreso; XXII Congress of the Scandinavian Plant Physiology Society; 2005

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. The analysis of the natural genetic variation underlying this phenotypic variation may allow: 1) to identify genes that regulate important traits for plant productivity (like growth arrest, leaf senescence, resistance to biotic stress), 2) to address ecological questions related to population structure and evolution.             To set up the collection, root cuttings from Swedish aspen were taken from 12 different populations across Sweden, from 56° NL (Ekebo) to 66° (Luleå). From these cuttings trees were obtained and planted in two sites: Ekebo and Sävar during June 2004, and the collection are also grown under controlled conditions in the greenhouse. During the 2004 season phenotypic data was collected. For example, growth arrest occurs first in populations from Northern Sweden in both sites, but earlier in Ekebo (56° NL) than in Sävar (64° LN).             The next steps in the analysis of the collection will be: a) Phenotyping other traits during the second year, like bud flush, bud set and start of leaf senescence, and b) Genotyping the collection: we have started to genotype the collection using microsatellites markers and sequencing of candidate genes for important traits.