The PNWTIRC developed an approach for genetically improving fall cold hardiness in Douglas-fir. Stem sections are collected from field progeny tests and cold hardiness is measured using artificial freeze tests in the laboratory.

PNWTIRC members include private companies and governmental organizations that develop and use genetically improved seedlings for reforestation in the Pacific Northwest.

Our research now focuses on developing genetic markers for enhancing Douglas-fir tree breeding. We are using genetic markers called SNPs, which are single-letter differences in the genetic code that can be measured using genotyping arrays.

The PNWTIRC developed methods for genetically improving wood stiffness using non-destructive acoustic tools. Oguz Urhan, a graduate student from Turkey, is shown measuring Douglas-fir wood stiffness using a Fakopp acoustic tool.

The timing of spring bud flush is an important adaptive trait in forest trees because it is closely associated with spring frost damage. The PNWTIRC has studied the genetics of bud flush and other adaptive traits.

The PNWTIRC developed flower induction methods for young Douglas-fir trees in miniaturized seed orchards. Jim Smith is shown injecting a Douglas-fir graft with gibberellic acid to induce flowering and cone production.

We recently completed a 15-year study of Douglas-fir miniaturized seed orchards (MSOs). MSO trees are planted at close spacings and maintained at heights of only 2 to 4 meters to increase per-hectare seed yields and facilitate orchard management.

We are collaborating with the USFS Dorena Genetic Resource Center and Inland Empire Tree Improvement Cooperative to develop molecular genetic markers for western white pine. These markers will be used to enhance resistance to white pine blister rust.

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The Pacific Northwest Tree Improvement Research Cooperative (PNWTIRC) was formed in 1983 to conduct research in support of operational tree improvement in the Pacific Northwest. Today, the cooperative has 14 member organizations, and is housed in the Department of Forest Ecosystems and Society at Oregon State University. Glenn Howe is the Director of the Cooperative.