1. Daniel B. Warnell School of Forestry and Natural Resources; University of Georgia; Athens GA 30602 USA
2. Institute for Genomic Biology; University of Illinois; Urbana IL 61801 USA
3. Laboratory of Plant Ecology; Faculty of Bioscience Engineering; Ghent University; Ghent B-9000 Belgium
4. Department of Crop Protection; Faculty of Bioscience Engineering; Ghent University; Ghent B-9000 Belgium