1. Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A;
2. Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331, U.S.A;
3. U.S. Department of Agriculture-Agricultural Research Service, Forage Seed and Cereal Research Unit, Corvallis, OR 97331, U.S.A;
4. Washington Hop Commission, Yakima, WA 98901, U.S.A