Characterization of Pseudomonas cichorii isolated from different hosts in Turkey

Stem and pith necrosis symptoms on tomato, varnish spot symptoms on lettuce and leaf spot symptoms on dwarf umbrella trees were observed in late winter and spring of 2002 and 2008 in the Eastern Mediterranean region of Turkey. Fluorescent bacteria were isolated from typical diseased plants on King's medium B as nearly pure cultures. All of the bacterial strains isolated in the study were identified as Pseudomonas cichorii compared with reference strains GSPB 2097, CFPB 2102 and NCPPB 3802, based on conventional methods, ELISA and fatty acid methyl ester analysis. The strains were divided into five different groups according to cluster analysis of fatty acid compositions in phenotypic characterization of the strains. In sensitive assays, tomato, lettuce and dwarf umbrella trees strains are sensitive to cupric sulfate and streptomycin. The study also demonstrated that P. cichorii strains isolated from tomato, lettuce and dwarf umbrella trees can be distinguished based on BOX-PCR experiments in genotypic characterization of the strains. In pathogenicity tests, tomato and lettuce strains were more aggressive on tomato, lettuce and dwarf umbrella trees, while dwarf umbrella trees strains were pathogenic only on their host. When strains were inoculated to their original host, they were more aggressive on their host than on other species. This is the first detail study of P. cichorii causing stem and pith necrosis on tomato, bacterial rot and varnish spot on lettuce and leaf spot on dwarf umbrella trees in Turkey. © 2011 Friends Science Publishers