Abstract
Pseudomonas syringae pv. syringae causes canker, leafspots and necrosis of the bark of cherry, plum, and peach fruit trees. Symptoms caused by this pathogen on leaves, blossoms, and fruit, reported as common else where, are rare in Guilan cherry orchards. In this research, during survey from cherry, plum, and peach orchards in different areas of Guilan province (Talesh, Hashtpar, AstanehAshrafieh and Lahijan), samples were taken from infected tissues of disease trees. For isolation of bacterial causal disease, infected tissue were crushed in pepton water then 100µL of juice were cultured on Nutrient Agar (NA) and King’s B medium containing Cyclohexamid antibiotic (50 µg mL-1 ). Strains of bacteria rod-shaped, gram negative and aerobic bacterium were isolated. The strains produced Levan on media including sucrose. All strains made Hypersensitive Reaction (HR) on tobacco and Geranium leaves. All of the isolated bacteria were oxidase, nitrate, tween 80 hydrolysis, indole and starch hydrolysis negative and could not rot potato tuber slices, produce H2S, and grow in 36°C. The isolates could use citrate and urease. The isolates produce acid from sorbitol, galactose, myo-inositol, manitol, xylose, maltose and sucrose. Their gelatin test were positive. Based on morphological, physiological, biochemical, pathogenicity properties, total cellular protein profiles (SDS-PAGE) and PCR method with specific primers the predominate pathogenic type was identified as P. s. pv. syringae. This is the first report of the existence of P. s. pv. syringae on stone fruit trees in Iran.
