In human genetics, association mapping is a method used to identify the genes behind different traits. In the last issue of Genetics, UPSC researchers show that the same technique can be used to identify the genetic basis of important traits in a tree (aspen, Populus tremula). In addition, the resolution of the mapping is higher than in the case of humans so the genetic differences potentially can be mapped down to the single nucleotide polymorphism (SNP), due to the low linkage disequilibrium (LD) in the Populus genome. The paper "Nucleotide polymorphism and phenotypic associations within and around the phytochrome B2 locus in european aspen (Populus tremula, Salicaceae) by PK Ingvarsson, MV Garcia, V Luquez, D Hall and S Jansson is available in the scientific journal Genetics: e-link to journal