Further Agglutination Tests with Bacterial Plant Pathogens. I. Bacterium campestre-Bact. phaseoli Group; Bact. medicaginis Var. Phaseolicola; Bact. Tumefaciens

Abstract

The agglutination test can be used to differentiate Bacterium malvacearum from the yellow organisms Bact. campestre, Bact. phaseoli, Bact. citri, Bact. cucurbitae, and Bact. pruni. When the antiserum of Bact. malvacearum is tested against suspensions of Bact. phaseoli sojense, a specific differentiating test is obtained; when the anti-serum of Bact. phaseoli sojense is used against suspensions of the homologous organism and of Bact. malvacearum the direct agglutination test is not specific and differentiating. Serologically Bact. malvacearum is more closely related to Bact. phaseoli and Bact. phaseoli sojense than to Bact. campestre. The yellow organisms tested probably are not a single group serologically. Bact. campestre, Bact. malvacearum, Bact. phaseoli, Bact. phaseoli sojense, and Bact. flaccumfaciens apparently constitute a serological group. Bact. medicaginis var. phaseolicola can be differentiated by the agglutination test from the bean pathogens Bact. phaseoli, Bact. phaseoli sojense, and Bact. flaccumfaciens. When the antiserum of Bact. tumefaciens is tested against suspensions of the homologous and of various heterol-ogous organisms, highly specific agglutination occurs; when the antisera of these heterologous organisms are tested against suspensions of Bact. tumefaciens, agglutination generally takes place in the lower dilutions.