1994年秋季，在河北、黑龙江、内蒙、甘肃部分马铃薯种植区采集晚疫病病叶或病薯，共分离到66个菌株。在室内用‘渭薯1号’进行活体测定，瑞毒霉设0．01，0．1，1，10，100，1000mol／L等6个浓度梯度和1个空白对照，结果表明：有33．3％的菌株对瑞毒霉表现高度抗性，43．9％的菌株表现为中度抗性。抗性的发生往往是伴随这个地区连续使用瑞毒霉后而出现的。 In the autumn of 1994, late blight leaves or diseased tubers were collected from some potato planting areas in Hebei, Heilongjiang, Inner Mongolia and Gansu, and 66 strains were isolated. In vivo determination of in vivo with ’Ixu 1’, six concentrations gradients of 0.01, 0.1, 1, 10, 100, 1000mol / L of Renshenium was set up, and a blank control showed that 33 Three percent of the strains showed high resistance to R. reinhardtii, and 43.9% of the strains showed moderate resistance. The occurrence of resistance often comes with the continuous use of Rameella in this area.