title: Widespread, ecologically relevant genetic markers developed from association mapping of climate-related traits in Sitka spruce (Picea sitchensis).
abstract: • Genecological studies in widespread tree species have revealed steep genetic clines along environmental gradients for climate-related traits. In a changing climate, the ecological and economic importance of conifers necessitates an appraisal of how molecular genetic variation shapes quantitative trait variation, and one of the most promising approaches to answer this question is association mapping. • We phenotyped a wide collection of 410 individuals of the widely distributed conifer Sitka spruce rangewide (Picea sitchensis) for budset timing and autumn cold hardiness, and genotyped these individuals for a panel of 768 single nucleotide polymorphisms (SNPs) representing > 200 expressed nuclear genes. • After correcting for population structure, associations were detected in 28 of the candidate genes, which cumulatively explained 28 and 34% of the phenotypic variance in cold hardiness and budset, respectively. Most notable among the associations were five genes putatively involved in light signal transduction, the key pathway regulating autumn growth cessation in perennials. Many SNPs with phenotypic associations were also correlated with at least one climate variable. • This study represents a significant step toward the goal of characterizing the genomic basis of adaptation to local climate in conifers, and provides an important resource for breeding and conservation genetics in a changing climate.
authors.affiliation: Department of Forest Sciences, University of British Columbia, Vancouver, BC, Canada. jah1@vt.edu
authors.forename: Jason A
authors.initials: JA
authors.lastname: Holliday
authors.forename: Kermit
authors.initials: K
authors.lastname: Ritland
authors.forename: Sally N
authors.initials: SN
authors.lastname: Aitken
mesh_terms: D002874:Chromosome Mapping / Q000379:methods*; D002980:Climate; D016000:Cluster Analysis; D017753:Ecosystem; D005787:Gene Frequency / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D056726:Genetic Association Studies; D005819:Genetic Markers; D014644:Genetic Variation; D005843:Geography; D010641:Phenotype; D010802:Phylogeny; D028222:Picea / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011157:Population Dynamics; D019655:Quantitative Trait, Heritable; D012044:Regression Analysis
chemical_list: D005819:Genetic Markers