1. Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, U.S.A.
2. International Maize and Wheat Improvement Center (CIMMYT), Texcoco C.P. 56237, Mexico
3. Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, U.S.A.
4. Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.
5. Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A.
6. Mycology and Nematology Genetic Diversity and Biology Laboratory, U.S. Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD 20705, U.S.A.