1. Crop and System Sciences Division, International Potato Center (CIP), Apartado 1558, Lima 12, Peru
2. Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA
3. Department of Primary Industries and Regional Development, 3 Baron-Hay Court, South Perth, WA, Australia
4. Laboratory of Plant Virology, Department of Applied Biological Sciences, Faculty of Agriculture, Saga University, 1-banchi, Honjo-machi, Saga, Japan