Population Genomics of Cold Adaptation in Poplar

PI: Matthew S. Olson, University of Alaska Fairbanks

CoPI: Peter Tiffin, University of Minnesota

Populus species are economically, ecologically, and environmentally important; they are harvested for paper pulp and particle board production, and hold potential for playing important roles in CO2 biosequestration and biofuel production. Populus also is the model organism for hardwood tree genomics and physiology. Population genetic tools are increasingly useful for identifying genes that underlie variation in ecologically and economically important traits, but are not presently available in Populus. This project will develop these tools for Populus balsamifera, use them to identify the genetic basis for phenotypic variation in bud set (an important determinant of cold adaptation and growth rate). This research also will test whether the same genes responsible for variation and adaptive evolution of bud set in North American P. balsamifera and European P. tremula. These objectives will be accomplished through collaboration with Canadian researchers who are establishing long-term common gardens of P. balsamifera. These common gardens will be maintained as a long term resource and are available to the wider scientific community; therefore, the data we generate will greatly facilitate future genotype-phenotype association analyses on additional economically and ecologically important traits (wood density, drought tolerance, etc.). The comparative population genomic analyses of adaptation to northern latitudes will be accomplished through collaboration with colleagues at the University of Umea, Sweden, who are conducting complementary research in European aspen (P. tremula).

Broader impacts and intellectual merit: This project will provide numerous training opportunities in plant genomics and bioinformatics for undergraduate students, graduate students, and post-doctoral researchers. Training for undergraduate students will focus on developing and conducting scientific research and written and verbal communication of results. Research opportunities will be made available to Native Alaskan students through University of Alaska Fairbanks ANSEP Program. Graduate students and post-doctoral researchers will receive more in-depth training in scientific inquiry, communication of results, and mentoring. The research will form the basis for the development of laboratory exercises in DNA sequence analysis, population genomics, and association mapping for undergraduate courses. These exercises will be developed in courses taught at the University of Alaska and the University of Minnesota and made freely available to the larger educational community through our project web site and the plant genome outreach portal (http://www.plantgdb.org/PGROP/pgrop.php). Finally, this research will illuminate the population genomics of a keystone species of Arctic boreal communities and the tree with the northernmost distribution in North America, complementing the themes of International Polar Year (2007-2008).

All genomic tools, data, and biological materials generated by this project will be made publicly available through our project website at http://biotech.inbre.alaska.edu/PPG/ and through the Poplar Genome Portal http://www.populusgenome.org/. These materials will greatly facilitate, in time and money, future association analyses of functionally-important genes in poplar.