1. USDA-ARS, Dep. of Horticulture; Univ. of Wisconsin; 1575 Linden Dr. Madison WI 53706-1590
2. Global Crop Diversity Trust; Viale delle Terme di Caracalla; 00153 Rome Italy
3. Instituto Nacional de Tecnología Agropecuaria- Universidad Nacional de Mar del Plata and CONICET; C.C. 256, 7620 Balcarce Argentina
4. International Potato Center; P.O. Box 1558 La Molina Lima 12 Peru
5. Plant Breeding and Acclimatization Institute- National Research Institute; Młochów Research Center; 19 Platanowa, 05-831 Młochów, Poland
6. Dep. of Plant Science; Federal Univ. of Santa Maria; CEP 97105-900, Camobi Santa Maria Brazil