1. Institute of Biology, Komi Science Center, Russian Academy of Sciences, 167982, Kommunist. st., 28, Syktyvkar , Komi Republic, Russian Federation
2. Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå , Sweden
3. Department of Forestry, North Central Research and Outreach Center, University of Minnesota, 1861 Highway 169 East Grand Rapids , MN 55744, USA