Streptomyces manipurensis MBRL 201T as potential candidate for biocontrol and plant growth promoting agent for rice

741-749Globally, there is a need to enhance agricultural productivity safely to feed the growing human population without massive use of chemical pesticides and fertilizers, as it causes adverse effects on environment. Biocontrol activities and use of plant growth promoting (PGP) bacteria holds great promise for an ecofriendly sustainable organic agriculture. In this context, here, we studied a novel species, Streptomyces manipurensis MBRL 201T for its biocontrol and growth promoting potential in rice. It was found to exhibit antagonistic activity against 6 important rice fungal pathogens by diffusible and volatile compounds production. The culture filtrates also exhibited significant inhibition. The strain was positive for PKS-II and NRPS genes. The strain produced fungal cell wall degrading enzymes, such as chitinase, β-1,4-glucanase, lipase and protease, and volatile compound, such as ammonia. The strain could produce 50.05 µg mL-1 of IAA, highest siderophore in starch casein nitrate broth (88.05%) and solubilize 76 µg mL-1 of phosphate. The strain was also positive for ACC deaminase activity. Highest vigor index was observed when rice seeds were treated with 6×107cfu mL-1 of MBRL 201T. The strain could enhance seeds germination and growth of rice seedlings even under pathogen challenged conditions. Treatment of the strain through seeds dipping and foliar spray exhibited significant effects on growth of rice under greenhouse and field conditions. The strain has the potential to be used as biocontrol and/ biofertilizing agents for application in rice plant