Characterization and host range evaluation of Pseudomonas viridiflava from melon, blite, tomato, chrysanthemum and eggplant

The fluorescent bacterium Pseudomonas viridiflava (Burkholder) Dowson was identified as the causal agent of bacterial leaf blight of melon, tomato, blite, eggplant and of pith necrosis of chrysanthemum plants. Koch's postulates were fulfilled on greenhouse-grown or on potted plants under controlled environmental conditions. Twenty seven cultivated and one weed species, when artificially inoculated, were found to be susceptible to a strain of the bacterium isolated from cucumber. In cross-inoculation tests on potted plants, each strain induced the disease symptoms, independently of the host of origin. To our knowledge, melon and blite have not been previously reported as natural hosts of P. viridiflava. Also this is the first record of the bacterium as a foliar pathogen of melon, tomato, eggplant and blite and as a stem pathogen of chrysanthemum in Greece.