Molecular Selection Tools in Adaptive Phenology of Populus trichocarpa Breeds for the Nordic-Baltic Region

Abstract

Fast-growing poplars have the potential to improve the biomass supply required for the transition to bio-based economies in the Nordic-Baltic region. As early successional trees, poplars are efficient biomass producers in relatively short rotations, when high-yielding, climate-adapted clones are available for commercial deployment. In Sweden, poplar breeding focused on adapting Populus trichocarpa to the Swedish climate by crossing parents from distant populations along latitudinal and maritime-continental clines on the Pacific coast of North America. Clonal trials with progeny from these crosses were established in the Nordic-Baltic region. Elite individuals in terms of stemwood production were used to identify candidate genes for adaptation to local photoperiod and climate in the region. The next breeding cycle utilized the elite individuals in the clonal trials to generate a training population. Genomic selection of the progeny in the training population will facilitate early selection of poplar clones for commercial deployment in the Nordic-Baltic region and reduce the time required for successive plant breeding cycles.