According to the resistance performance of clubroot in the field, two kinds of rapeseed materials, Kc84-1 and OG-13, which were resistant to the No.4 physiological race of Plasmodiophora brassicae, were preliminarily screened out by the bacterial soil method and the dipping root method among the several suspected disease resistant materials. The clubroot resistance of material Kc84-1 was identified by comparing with the resistant cultivar Huashuang 5R and the susceptible material R-197 by the disease investigation statistics, and the related resistance physiological analysis of three materials was carried out. The results showed that, there was the same level clubroot resistance of Kc84 1 and Huashuang 5R. The activity of defense enzymes Superoxide Dismutase (SOD), Peroxidase (POD), Polyphenol oxidase (PPO), Phenylalanine ammonialyase (PAL) and the Malondialdehyde (MDA) content of resistance related substances were different in distinct materials. The activities of the two kinds of resistant materials, such as SOD, POD, and PAL, were significantly higher than that of the susceptible material. There was no significant difference in PPO activity and MDA content between resistant materials and susceptible materials. The observation on root hair infection of three materials at an early stage by hydroponics, the results showed that the root hairs infection rate of susceptible material R-197 was significantly higher than that of resistant varieties Huashuang 5R and material Kc84-1 in the sixth to fourteenth days of infection.
