IAN MACLACHLAN

Evaluating genome-wide effects of selective tree breeding on adaptive diversity

Ian is a PhD Candidate in the University of British Columbia’s Department of Forest and Conservation Sciences. Ian has a lifelong passion for trees, forests, their diversity and the timber they produce. His primary research interest is the question of how molecular genetic information can be integrated into sustainable forest management and conservation that respects historical gene flow and the adaptive variation shaping contemporary genetic structure in forest ecosystems.

Currently, over 64% of reforestation seedlots deployed on provincial land in British Columbia come from advanced generation selective breeding programs. While we know the effects of this selective breeding on genetic gain and diversity, the genome-wide impacts of selective tree breeding are unknown. This limits our evaluation of how assisted migration strategies may be used safely to mitigate decreases in forest productivity due to climate change.

As part of AdapTree, his research will compare reforestation seedlots from natural stands and selective breeding programs. For two conifer species; lodgepole pine and interior spruce (white spruce, Engelmann spruce and their natural hybrids), he has established seedling common gardens of ~3000 individuals to provide phenotypic data on several climatically and silviculturally relevant traits, and be genotyped for a suite of >1500 adaptive SNPs (DNA sequence variations). By making carefully selected phenotypic and population genomic comparisons between seedlot types, he aims to determine whether selective breeding causes adaptive deviations from populations under natural selection. The findings will allow an evaluation of the current provincial seedlot diversity standards, and provide vital information to guide the development of assisted migration policies for selectively bred seedlots that strive to maintain forest productivity in British Columbia and Alberta.