1. Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331–2902
2. National Veterinary Institute, Section of Food & Feed Microbiology, Ullevålsveien 68, P.O. Box 8156 Dep. 0033 Oslo, Norway
3. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, P.O. Box 3800, 1055 rue du P.E.P.S., Sainte-Foy, QC G1V 4C7 Canada
4. Department of Botany, University of Toronto, Erindale Campus, Mississauga, Ontario L5L 1C6 Canada