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.

晚疫病（LB）是世界范围内的主要马铃薯病害，控制它的最重要方法之一是使用抗性品种。来自国际马铃薯中心开发的具有高抗病性的 B3 育种群体的 22 个马铃薯克隆和两个易感对照的马铃薯克隆接种了 4 个秘鲁复杂分离株（POX67、PPA61、PLL69 和 PPI112）的致病疫霉，对马铃薯具有复杂的毒力。在秘鲁利马的温室和潮湿室条件下进行了全植物接种试验，获得的数据与在秘鲁雨林的 CIP 繁殖地 Oxapampa (Pasco) 进行的田间试验数据相关联。马铃薯无性系对LB的抗性表现出高度显着相关（α=0.01），温室条件下分离株POX67、PPA61和PLL69与田间抗性的相关值分别为r = 0.93、0.92和分别为 0.80，在潮湿室条件下分别为 r = 0.94、0.93 和 0.94。在田间和温室 (r = 0.69) 和田间和潮湿室条件下 (r = 0.77) 接种 PPI112 分离株的抗性之间存在中度相关性。