Study on angular leaf spot causing bacteria of pumpkin (Cucurbita pepo, C. maxima) and evaluation of its sensitivity

The present inquisition was conveyed to isolation, characterization of Pseodomonas syringae pv. Lachrymans bacterium from angular leaf spot disease of pumpkin and evaluation of its biological control. The isolated bacterium was characterized by different biochemical test. The isolate performed gram negative, rod shaped and pink color in gram staining test. It showed positive result in Catalase, Indole, Simmon’s citrate, MacConkey agar, Potassium hydroxide, Methyl Red test and negative to Motility and Urease test. In Triple Sugar Iron and Kligler Iron Agar test, the bacterium fermented the carbohydrates. Antibiotic and antimicrobial activities were screened by disc diffusion method.The highest 22±0.0mm diameter of zone of inhibition was observed by Cefotaxime in 30µg/disc concentration against the isolated bacterium. Adhatoda vasica showed the highest antimicrobial activity with inhibition zone 12.1±0.2mm that means the plant extract had antimicrobial activity against the isolated bacterium. The present research could be helpful for biological control of this devastating disease.