Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Forest Trees
            

QUANTITATIVE TRAIT LOCI CONTROLLING ADAPTIVE TRAITS IN COASTAL DOUGLAS-FIR. III. QTL BY ENVIRONMENT INTERACTIONS AND VERIFICATION

¹ Institute of Forest Genetics, US Forest Service-PSW, 2480 Carson Road, Placerville, CA, USA, 95667

² Weyerhaeuser Technical Center, 9777 Federal Way, WA, USA, 98063-9777

³ Department of Environmental Horticulture, University of California at Davis, Davis, CA, USA, 95616

Genotype x environment interactions for adaptive traits in forest trees have been studied by traditional quantitative methods but, to our knowledge, the individual QTLs interacting with environmental signals have not been identified in controlled experiments. We have cloned a large number of progeny from a 3-generation pedigree for the purpose of estimating QTLs interacting with key environmental signals governing seasonal growth. Specifically, we tested 1) two levels of winter chill and three levels of spring flushing temperatures on spring terminal bud flush, and 2) two levels of daylength and two levels of moisture stress on growth cessation and related growth rhythm traits. An all-marker interval mapping method was used for detection of QTLs, and single-factor ANOVA was used for detecting QTL x treatment (QTLxT) interactions. Several QTLs were detected following the 1-QTL model and the proportion of phenotypic variation explained by individual QTLs were small to moderate (0.7% - 9.5%). Treatments had a significant effect on phenotype and few to several QTLxT interactions were found for each trait. Co-location of QTLs and QTLxT interactions was observed among traits associated with predetermined-growth derived from an overwintering bud. Likewise, co-location of QTLs and their interactions with treatment was observed among traits contributing to or resulting from free-growth derived from a neo-formed bud (lammas). We compared QTLs for bud flush detected in four genetic tests with those that were detected in a previous QTL study. Six QTLs were found in common between two replicated field tests; subsets of these QTLs were also detected in two greenhouse trials and an earlier study.