The role of tree improvement programs for ex situ gene conservation of coastal Douglas-fir in the Pacific Northwest.

Abstract

We enumerate the genetic resources for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in tree improvement programs in the Pacific Northwest USA and evaluate how they contribute to gene conservation of the species. The first-generation programs include over four million progeny from 33,928 selections planted on 999 test sites. Nearly 2,000 of the selections tested in the first-generation have been incorporated into second-generation programs. The first-generation tests serve as repositories for low-frequency alleles of potential future import and for variation in quantitative traits not presently under selection. Much of this genetic variation also resides in the many large in situ populations of Douglas-fir, but it can be more easily detected in genetic tests. Additionally, useful genetic variation can be more rapidly integrated into tree improvement programs with the least loss of genetic gain if it is identified in genetic tests rather than in in situ populations. Because first-generation genetic tests are of limited life we develop a method for creating gene resource outplantings to retain for a longer period the valuable genetic resources in them.

Citation

Lipow, Sara R.; Johnson, G. Randy; St. Claiff, J. Bradley; Jayawickrama, Keith J. 2003. The role of tree improvement programs for ex situ gene conservation of coastal Douglas-fir in the Pacific Northwest. Forest Genetics. 10(2): 111-120