Abstract. Phurejas potatoes (Solanum phureja Juz et Buk) are cultivated in very restricted areas of the Bolivian Andes. Late blight caused by Phytophthora infestans is a destructive, endemic disease that affects the survival and cultivation of this crop. The aim of this study was to determine the resistance characteristics of phurejas potato varieties to P. infestans in a traditional area of cultivation.
An experimental plot was prepared in the locality of Chojchoni (3200 m) and planted with different phurejas varieties: 1) Chojllu Phureja (Sste); 2) Phureja Amarilla (Sphu); 3) Polo Phureja (Sphu); 4) PhurejaRoja (Sphu); 5) Phureja Negra (Sphu) and 6) Waych’a Paceña (Sadg), a susceptible control. Severity was assessed according to the criteria of the Centro Internacional de la Papa, determining the area under the disease progress curve (AUDPC). Regression analysis (log N disease severity against time) was performed using the logistic model [ln(y/1-y)]to determine infection rates. The different varieties showed different levels of resistance. The disease progress curve, the AUDPC and the linear regression results revealed the varieties Chojllu Phureja, Phureja Amarilla and Polo Phurejato likely have larger copy numbers of minor resistance genes against P. infestans than Phureja Roja or Phureja Negra. Late blight caused by P. infestans could cause the long-term loss of some phurejas varieties through farmers selecting others less severely affected by the disease.
Mario Coca-Morante and Ismael Tolín-Tordoya. American Journal of Plant Sciences, 2013, 4, 53-58.
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