1982年7～8月份在内蒙地区的大白菜上发生了一种细菌性病害。它主要危害植株的叶片,形成圆形或不规则的枯斑,并可愈合成大的枯黄斑。根据病原细菌在形态、染色反应、培养性状、生理生化和血清学等方面的研究,该病原细菌是属于丁香假单孢菌的一个致病变种Pseudomonas syringae pv.maculicola(McCulloch,1911)Young.Dye and Wilkie 1978。 该菌系在大白菜上表现有较强的致病力,引起的症状比文献上所报道的严重。 A bacterial disease occurred on Chinese cabbage from July to August 1982 in Inner Mongolia. It mainly harms the leaves of plants, forming round or irregular spots and healing to large, yellowish spots. According to the pathogenic bacteria in morphology, staining reaction, culture traits, physiology and biochemistry and serology, the pathogenic bacteria is a pathogenic strain of Pseudomonas syringae pv. Maculicola (McCulloch, 1911) Young.Dye and Wilkie 1978. The strain shows strong pathogenicity in Chinese cabbage and causes more serious symptoms than those reported in the literature.