1. Département de Microbiologie Fondamentale; Université de Lausanne; Bâtiment Biophore; Quartier UNIL-Sorge; CH-1015; Lausanne; Switzerland
2. USDA-ARS National Forage Seed Production Research Center; Corvallis; OR; USA
3. Department of Botany and Plant Pathology; Oregon State University; Corvallis; OR; USA