Thompson, Stacey Lee , Lamothe, Manuel , Levée, Valérie , Meirmans, Patrick G. , Isabel, Nathalie .
An applied population genomic approach to assess the risks posed by trees with novel traits.
Populus species and their hybrids are favoured for emerging applications in biofuels, carbon sequestration and environmental remediation, yet the intentional planting of trees with novel traits can pose significant risks to the integrity of native species. We adopt an integrative approach to risk assessment that teams theoretical modelling with marker-based studies of gene flow in natural populations of native poplars, using exotic genes from introduced species as a proxy for any genomic invasion through sexual introgression. By genotyping thousands of trees, we demonstrate that exotic genes are passed to native trees adjacent to plantations through hybridization at significant frequencies (3-62%), that F1s are fertile, that 3% of broadly sampled individuals across 15 natural populations are of hybrid origin, that disturbed habitats are more apt to contain hybrids, and that introgression is consistently biased toward the native P. balsamifera. As the genome of balsam poplar appears most susceptible to infiltration, we are presently genotyping 1500 trees throughout the distribution (using SNPs from 99 genes) to study the genetic structure of natural populations and evaluate molecular evidence for selective sweeps. These features will dictate the extent to which introduced DNA could spread throughout the range of the native species. The risks posed by trees with novel traits need to be considered in light of the extensive contamination that has already occurred by exotic poplars, as well as the fitness effects of the traits in question.
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1 - Natural Resources Canada, Canadian Forest Services, Laurentian Forestry Centre, 1055, rue du PEPS, C.P. 10380, Succursale Sainte-Foy, Québec, QC, G1V 4C7, CANADA
genomics-derived genetic engineering
Presentation Type: Oral Paper:Papers for Topics
Date: Tuesday, July 29th, 2008
Time: 10:30 AM