S.P. KAMALA NALINI P. SARA VANAN, A. ARUMUGAM AND D. LALITHAKUMARF
Abstract
The present investigation revealed Pseudomonas chlororaphis as a potential hiocontrol strain. The pseudomonad inhibited a wide range of phytopathogens, but was non-inhibitory to beneficial soil organisms. The cell free culture filtrate had an inhibitory effect on the radial growth of the test fungi, this antagonistic potential of the pseuclomonad was attributed to the production of antibiotics. The aggressive spermosphere and rhizosphere colonization is an additional feature of the bacteria. The bacteria harbored one large plasmid of 140kb. The 140kb plasrnid was incurable but transferable to plasmid-less strain of Pseudomonas putida DSM 2112 (MTCC) indicating plasmid-mediated antibiosis. Transposon mutagenests and PCR analysis was done to confirm the role of plasmid in antibiosis. Field trails were done to confirm the potentiality of the bacterium as a novel biocontrol agent using paddy plants as model system.