1. Division of Gene Technology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 21, Box 2462
2. Division of Plant Biotechnics, Katholieke Universiteit Leuven, Willem De Croylaan 42, Box 2427, Leuven B-3001
3. Unit Plant—Crop Protection, Institute for Agricultural and Fisheries Research (ILVO), B. van Gansberghelaan 96, Merelbeke B-9820, Belgium
4. Department of Microbiology, Faculty of Medicine, Vanry Pavilion, Laval University, Quebec, QC G1K 7P4, Canada