Phenological and morphological responses of mesic and dry site sources of coastal Douglas-fir to water deficit

Journal Article

Transfer Guideline: Recommendation

Patterns of genetic variation in morphological and phenological responses to water deficit are described in seedling progeny of four populations of coastal Douglasfir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii ), sampled from coastal and inland sites in Oregon. Progeny of coastal and inland populations differed for all traits measured, and differences appear to reflect adaptation to the source environment. Inland populations were characterized by early budset, slower rates of shoot extension, and higher root-shoot ratios. A significant fraction of total variability was attributable to differences among families within populations. Little evidence for irrigation x population interaction was found when seedling traits were examined singly. Of 16 traits analyzed, only average daily rate of growth and seedling height had significant interaction terms. Interactions between irrigation and families-within-population were more prevalent. A canonical discriminant analysis was used to identify a subset of variables that best reveals differences among progeny of coastal and inland populations. Implications for seed transfer and for selection and breeding of genotypes suitable for xeric environments are discussed.