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Key message: Creation of second generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) hybrids based on parents from geographically distant locations did not appreciably increase variance in height, frost damage and bud break. New and favorable trait combinations between height and the two adaptive traits were found in the F2 populations. Context: Increased genetic variance and new trait combinations can improve selection efficiency in terms of selection response and increased adaptability. Aims: This project tested a novel method for generating higher genetic variance and new trait combinations in Douglas-fir populations. Methods: Parents from Southern British Columbia (BC), Washington (WA), Oregon (OR), and Northern BC (NBC) were crossed within each provenance; then selections from BC were crossed with the other sources to create three F1 interpopulation generations. Unrelated random selections from the same F1 population were subsequently crossed to produce three F2 populations. The parental, F1 and F2 generations were concurrently grown in three field tests and were evaluated for height, frost damage, and bud break date. Results: Significant segregation variances were found only in the BCxNBC cross for height in two sites and frost damage in one site and in the BCxOR cross for bud break in one site. In the BCxNBC cross, correlations between breeding values for height and frost damage changed from 0.71 in F1 to − 0.04 in F2 and between height and bud break from − 0.71 to − 0.26. In the BC-OR cross, correlations between height and bud break changed from − 0.71 in F1 to − 0.49 in F2. Conclusion: Our results suggest that creation of wide-cross hybrids may not be very effective in increasing segregation variance in traditional tree improvement programs but in some cases may be considered to increase diversity of trait combinations. [ABSTRACT FROM AUTHOR]

Presents a study of Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) zygotic seedlings and seedlings produced through somatic embryogenesis on southern Vancouver Island, British Columbia. Comparison of the two stock types in a number of adaptive attributes evaluated during two growing seasons; Methods; Findings; Indication that somatic and zygotic seedlings had a similar pattern of physiological performance throughout two years of assessment.

Many current tree improvement programs are incorporating assisted gene flow strategies to match reforestation efforts with future climates, This is the case for the lodgepole pine (Pinus contorta var. lati:folict). the most extensively planted tree in western Canada. Knowledge of the structure and origin of pathogen populations associated with this tree would help improve the breeding effort. Recent outbreaks of the Dothistroma needle blight (DNB) pathogen Dothistroma septosporum on lodgepole pine in British Columbia and its discovery in Alberta plantations raised questions about the diversity and population structure of this pathogen in western Canada. Using genotyping-by-sequencing on 119 D. septospon, m isolates from 16 natural pine populations and plantations from this area, we identified four genetic lineages, all distinct from the other DNB [ineages from outside of North America. Modeling of the population history indicated that these lineages diverged between 31.4 and 7.2 thousand years ago, coinciding with the last glacial maximum and the postglacial recolonization of lodgepole pine in western North America. The lineage found in the Kispiox Valley from British Columbia, where an unprecedented DNB epidemic occurred in the 1990s, was close to demographic equilibrium and displayed a high level of haplotypic diversity. Two lineages found in Alberta and Prince George (British Columbia) showed departure from random mating and contemporary gene flow, likely resulting from pine breeding activities and material exchanges in these areas. The increased movement of planting material could have some major consequences by facilitating secondary contact between genetically isolated DNB lineages, possibly resulting in new epidemics. [ABSTRACT FROM AUTHOR]