Plant & Animal Genome VI Conference

W46

QTL MAPPING OF ADAPTIVE TRAITS IN COASTAL DOUGLAS-FIR

1. Institute of Forest Genetics, PSW-USDA Forest Service, Placerville, CA, USA
2. Weyerhaeuser Forestry Research Center, Centralia, WA, USA
3. Department of Forest Science, Oregon State University, Corvallis, OR, USA
4. Department of Forest Sciences, University of British Columbia, Vancouver, British Columbia, CAN

We are using a map-based approach for identifying quantitative trait loci (QTL) effecting adaptive traits in coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii). A three-generation outbred pedigree that is segregating for date of budflush was used to construct a genetic linkage map using restriction fragment length polymorphism (RFLPs) and random amplified polymorphic DNA (RAPDs). Linkage analysis was performed on 217 loci segregating among the progeny using JoinMap version 2.0 (Stam and Ooijen, 1995). The result was a map comprised of 141 markers (126 RFLPs and 15 RAPDs), organized into 17 linkage groups representing 1,062 cM with an average distance between markers of 7.5 cM. F₂ progeny were clonally propagated and planted in replicated test sites in Oregon and Washington. Various adaptive traits were measured on the progeny in 1995, 1996 and 1997. A subset of evenly distributed markers that were highly informative were selected for genotyping 192 of the outplanted progeny. These data have been analyzed to estimate QTL effecting bud flush and spring and fall cold-hardiness using an interval mapping method customized for outbred tree pedigrees (Knott et al. 1997).