1. Edmonto n, AB, Canada
2. Department of Agricultural, Food and Nutritional Science University of Alberta, Edmonton , AB, Canada , T6G 2P5
3. Alberta Tree Improvement and Seed Centre, Alberta Sustainable Resource Development, Smoky Lake , AB, Canada , T0A 3C0.
4. Alberta Tree Improvement and Seed Centre, Alberta Sustainable Resource Development, Smoky Lake , AB, Canada , T0A 3C0