On the Strains of Erwinia carotouora subsp. carotouora Isolated from Radish Seedlings and Broccoli Plants

Twenty bacterial strains isolated from edible radish seedlings (Kaiware-daikon: Raphunus sativus L.) and broccoli plants (Brassica oleracea var. italica Plen.) showing soft rot were compared on the basis of pathogenicity and physiological, biochemical and serological properties. Ten strains isolated from each host were homogeneous and they were identical in being positive for the following properties: rod shaped cells with peritrichous flagellation, anaerobic growth, fermentative metabolism of glucose, growth at 36”C, catalase, H,S production, pectate degradation, gelatin liquefaction, nitrate reduction, utilization of lactose, rhamnose, trehalose and citrate. They were also identical in being negative in the following tests: Gram stain, oxidase, production of reducing substances from sucrose, amino acid decarboxylases, phosphatase, utilization of maltose,a-methyl glucoside, palatinose, malonate and tartrate. Casein hydrolysis was variable. From these results both strains were identified as Eminia carotovora subsp. carotovora. These strains caused soft rot by inocula-tion to slices of potato, carrot and cucumber as well as to radish seedlings and detached broccoli tissues. The pathogenicity to onion and tomato, however, was different between the radish strains and broccoli strains, suggesting variation in pathogenicity. Bacterial strains from either radish seedling or broccoli were distinguishable each other in the serological reaction (agar gel diffusion test) to their reciprocal antisera