Chitinase-mediated destructive antagonistic potential of Pseudomonas aeruginosa GRC 1 against Sclerotinia sclerotiorum causing stem rot of peanut

Pseudomonas aeruginosa GRC 1 exhibited strong antagonistic activity against Sclerotinia sclerotiorum, in vitro and in vivo . Scanning electron microscopic (SEM) studies showed morphological abnormalities such as perforation, lysis and fragmentation of hyphae of S. sclerotiorum caused by P. aeruginosa GRC 1 . This strain produced extracellular chitinase enzyme, the role of which was clearly demonstrated through Tn 5 mutagenesis. Bacterization of peanut seeds with GRC 1 resulted in increased seed germination and reduced stem-rot of peanut in S. sclerotiorum -infested soil by 97%. Other vegetative and yield plant parameters such as nodules per plant, pods and grain yield per plant were enhanced with a statistical significance in comparison to control. Neomycin resistant (GRC 1 neo+ ) bacterium was a good root colonizer and frequently isolated from rhizosphere of peanut plants. These findings showed P. aeruginosa GRC 1 as a potential biocontrol agent against S. sclerotiorum .