Epiphytic survival of Pseudomonas viridiflava, causal agent of pith necrosis of tomato, on weeds in Turkey

Pith necrosis, caused by Pseudomonas viridiflava (Burkholder) Dowson, has been an important problem of greenhouse-grown tomatoes in the eastern Mediterranean region of Turkey since 1998. In the study, the epiphytic survival of P. viridiflava on weeds was investigated by using a semi selective agar medium (T-5) and indirect-ELISA in commercial greenhouses with a history of pith necrosis in three different locations of the region during 2001 and 2002. It is the first study showing that pathogenic strains of P. viridiflava on tomato may survive as an epiphytic population on the phyllosphere of Amaranthus spp., Conyza canadensis, and Orobanche ramosa in Turkey. The strains were identified as P. viridiflava by morphological, physiological, biochemical tests, indirect-ELISA and fatty acid methyl ester analysis, and were found to be pathogenic on tomato plants