First observation of pith necrosis on tomato caused by some pseudomonas species in Turkey

Pith necrosis of tomato caused by Pseudomonas viridiflava, P. cichorii and P. corrugata has been determined in commercial greenhouses in many countries including Turkey since the early 1990s. In the previous studies, P. viridiflava and P. cichorii have been reported as the main causal agents of the disease on tomatoes in Turkey. During 2003, a survey was conducted to determine disease incidence and identity of the bacterial pathogens causing pith necrosis on tomato grown in Mediterranean and Aegean regions of Turkey. Bacterial strains isolated from diseased plants on KB and NA media were identified on the basis of morphological, physiological, biochemical and pathogenicity tests. The identity of bacterial species was confirmed by fatty acid methyl ester analysis using Sherlock Microbial Identification System. The results showed that average disease incidence was 15-20%. Strains belonging to five different Pseudomonas species, i.e. P. fluorescens, P. mediterranea, P. viridiflava, P. cichorii and P. corrugate, were proven to be causal agents of pith necrosis on tomato plants examined in this study. This is the first report demonstrating that P. fluorescens and P. mediterranea cause pith necrosis on tomato in Turkey