Plant & Animal Genomes XVI Conference

January 12-16, 2008
Town & Country Convention Center
San Diego, CA

Genomics Of Adaptation In Douglas-Fir

David B Neale¹ , Barnaly Pande¹ , Andrew J Eckert² , Brandon R Tearse¹ , Jill L Wegrzyn¹ , Jennifer Lee² , Konstantin Krutovsky³ , John B St Clair⁴

¹  Department of Plant Sciences, University of California, Davis, CA, USA

²  Department of Evolution and Ecology, University of California, Davis, CA, USA

³  Department of Forest Science, Texas A&M University, 2135 TAMU, College Station, TX

⁴  USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, USA

We are interested in understanding the genetic basis of adaptation to the environment in natural plant populations. Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is highly adapted to the highly heterogeneous environments of the US Pacific Northwest and cataloged genetic changes over a ~300 million year evolution. It has been shown that winter temperatures and frost dates are most important for influencing the adaptation of Douglas-fir to these environments, and our previous studies have identified QTL for adaptation-related traits such as bud flush and cold hardiness in spring and fall seasons. Presently, we have resequenced differentially cold-regulated candidate genes emerging from studies of gene expression using Douglas-fir EST libraries. From the analysis of 100 genes using a diverse panel of trees, estimates the level of nucleotide diversity have been determined, as well as identification of genes showing evidence of selection using standard tests of neutrality. We have genotyped a subset of the identified SNPs in ~700 unrelated trees that range across the natural Douglas-fir forests of Washington and Oregon. Tests of association reveal 11 SNPs that individually account for up to 5% of the variation in adaptation-related traits, such as growth, cold-damage resistance and bud flush, following multiple testing correction. These findings pave the way for making more informed decisions regarding the conservation of genetic resources and management of Douglas-fir breeding programs, and for predicting, and possibly mitigating effects of climate change.