Tomato (Solanum lycopersicum L.) is a globally important vegetable crop, highly valued for its nutritional and economic significance. However, its productivity is often constrained by bacterial diseases, among which Pseudomonas viridiflava is an emerging phytopathogen responsible for leaf spots, blights, and fruit lesions. The present study aimed to isolate and characterize Pseudomonas viridiflava from diseased tomato plants grown in soil samples collected from Behror region of Rajasthan (India). Symptomatic plant parts, including leaves and fruits, were collected and subjected to bacterial isolation using Nutrient Agar (NA) medium. The isolated bacterial strain was purified and characterized based on morphological and biochemical tests, including Gram staining, catalase, oxidase, KOH, indole production, citrate utilization, cetrimide test, gelatin hydrolysis, arginine dihydrolase activity, and carbohydrate fermentation. The isolate was found to be Gram-negative, rod-shaped, catalase-positive, oxidase-negative, citrate-positive, indole-negative, and showed negative results for cetrimide, gelatin hydrolysis, arginine dihydrolase, and carbohydrate utilization tests. Based on these characteristics and comparison with standard taxonomic keys, the isolate was identified as Pseudomonas viridiflava. The study highlights the significance of biochemical characterization in the identification of plant pathogenic bacteria and provides baseline information for disease management strategies in tomato cultivation.
