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Genetics studies involving Swiss needle cast.

Informally Refereed

Abstract

Three studies were analyzed this year that examined genetic aspects of Swiss needle cast (SNC) tolerance . Families sampled across the Siuslaw National forest showed differences in foliage health traits, but very little of the variation could be explained by environmental or climatic conditions at the parent tree location. Five test sites of the Nehalem series of progeny trials were measured for DBH. The best families were continuing to have reasonable basal area increments, implying that genetic improvement can produce stock that could offset the 30% volume growth reduction predicted in moderately impacted SNC areas. A third study suggested that Douglas-fir families do not appear to increase 1st-year needle production in response to needle loss and families may differ in the amount of foliage the produce for a given branch diameter.

Three genetics studies looking at aspects of tolerance to SNC were completed this year. These studies examined the genetic variation patterns of SNC tolerance over the landscape, the effectiveness of genetically improving tolerance, and whether families differ in their ability to respond to SNC with increased needle production. The first study was supported by SNC Cooperative funding because it was done in conjunction with the early testing study. The second study was funded by the Oregon Department of Forestry and the TRASK metacooperative and the last study was established by the USFS PNW Research Station.

Citation

Johnson, R.; Temel, F.; Jayawickrama, K. 2002. Genetics studies involving Swiss needle cast. In: Filip, G. ed. Swiss needle cast cooperative annual report, 2002. [Corvallis, OR]: [Forest Research Laboratory, College of Forestry, Oregon State University]: 38-43
https://www.fs.usda.gov/research/treesearch/4928