Potato crop is expanding to areas with temperatures higher than those required. Climate change is increasing temperatures in traditional areas of potato production, thereby affecting tuber yield. The International Potato Center has developed a population adapted to these new conditions, being more tolerant to high temperatures, resistant to late blight, virus PVX and/or PVY and early maturity. In breeding programs it is very important to know the parental value of the progenitors. The parental value of 34 selected potato clones was determined through general combining ability for marketable, total yield and average tuber weight under high temperatures. Using the line by tester mating design, the potato clones were crossed as lines and varieties Katahdin, Huagalina and clones CIP398098.204 and CIP302533.31 as testers. The field experiments were carried out in three locations in Peru: San Ramon, La Molina and Majes, where average temperatures at night were between 15.25 to 21.65°C, and during the day fluctuated between 21.47 to 27.20°C. We used a randomized complete block design, with three replications. At harvest the number and weight of marketable and non-marketable tubers were taken. Then the average tuber weight, marketable and total yield per hectare was calculated. 18 potato clones were identified with high parental value for marketable yield, seventeen for total tuber yield and 11 for average tuber weight; nine of them combine high parental value for the three characteristics studied. These clones with late blight resistance, heat tolerant, adapted to medium altitudes, growing period of 90 days and high parental value can be used as parents in breeding programs, to obtain new varieties under the new climate change scenarios with high temperatures. 12 crosses that presented high SCA are the most promising for the development of superior clones.

Late blight (LB) is the main potato disease worldwide and one of the most important ways to control it is the use of resistant varieties. Twenty-two potato clones from the B3 breeding population developed by the International Potato Center with high resistance to the disease and two susceptible controls were inoculated with four Peruvian complex isolates (POX67, PPA61, PLL69, and PPI112) of Phytophthora infestans, with complex virulence on potato. Whole plant inoculation assays were carried out under greenhouse and humid chamber conditions in Lima, Peru, and data obtained were correlated with data from field assays carried out in Oxapampa (Pasco), a CIP breeding site in the Peruvian rain forest. High significant correlations (α = 0.01) were found in the resistance to LB shown by potato clones, the values of the correlations under greenhouse conditions between the isolates POX67, PPA61, and PLL69 with the resistance in the field were r = 0.93, 0.92 and 0.80, respectively and under humid chamber conditions were r = 0.94, 0.93 and 0.94, respectively. Moderate correlations were found between resistance in the field and in the greenhouse (r = 0.69) and the field and in humid chamber conditions (r = 0.77) for inoculations with PPI112 isolate. The twenty-two clones tested in this study showed phenotypic stability for LB resistance according to non-parametric analysis.

14Aplicación del modelo de Peleg para estudiar el efecto de la temperatura y dureza del agua durante la rehidratación de frijol caballero (Phaseolus vulgarias). RESUMENEn el presente trabajo se evaluó la aplicación del modelo de Peleg para estudiar el efecto de la temperatura y dureza del agua durante la rehidratación de frijol caballero (Phaseolus vulgarias), utilizando un diseño compuesto central rotacional (DCCR) obteniendo como resultados que la temperatura y la dureza del agua tienen un efecto positivo en la ganancia de peso durante la rehidratación de Frijoles. Además determinamos las constantes de Peleg K 1 (s.kg H2O /kg m.s ) y K 2 (kg H2O /kg m.s ). Palabras clave: Frijol caballero, rehidratación, modelo de Peleg ABSTRACTIn the present research Peleg model application was evaluated for study the effect of temperature and water hardness during the rehydration of caballero bean (Phaseolus vulgarias), using a center-rotational composed design, obtaining as result that temperature and water hardness have a positive effect during rehydration of beans. Peleg constants were also determinated K 1 (s.kg H2O /kg m.s ) y K 2 (kg H2O /kg m.s ).