The Williams identification system was adopted to identify the Plasmodiophora brassicae collected from the Chinese cabbage producing area at the mountainous areas in Yingjiang County,Yunnan
Province.The 4 differential hosts all showed that they were susceptible,and the disease index was 21、
33、28、30,respectively,indicating that fungus was physiological race No.4.The resistance of 18 Chinese
cabbage cultivars from home and abroad was identified by planting on fungal soil method.The results
showed that the incidence and disease indexes of 6 varieties were 0,and they were immune to Yingjiang Plasmodiophora brassicae.The disease index of 2 varieties were <10,indicating they were resistant to
Yingjiang Plasmodiophora brassicae.They could be used as resistant genetic resources for selecting new
Chinese cabbage varieties for this disease.