Induction of Bacterial Leaf Blight (Xanthomonas oryzae pv. oryzae) Resistance in Rice by Potential Endophytic Bacterial Consortium

Abstract

The world's most important food crop and the most important staple food for the expanding Indian population is rice (Oryza sativa L.). In many regions of the world, the disease has resulted in epidemic causing crop losses up to 50 per cent. Biocontrol has emerged as a useful tool in utilizing hostile microorganisms for a sustainable and friendly form of agriculture to protect crops from pathogens. Endophytes are microorganisms that reside inside the host plant and are known to be able to fight plant infections without creating any disease signs or negative effects. Since BLB of rice poses significant damage to rice farming and chemical control strategies are not viable, alternate fertilizers are being used to combat this problem by maintaining soil fertility and by increasing productivity. Isolated 52 bacterial endophytes from rice based on antagonistic activities against Xoo, based on biochemical characterization, plant growth promoting activities, nutrient solubilization and molecular characterization and compatibility four potential isolates EBP26, EBP39, EBP47 and EBP52 identified as B.subtilis, Pseudomonas fluorescence, Pseudomonas sp. and Pantoea dispersa developed as bacterial consortium. Application of microbial consortium under glass house and induction of defence enzymes (PAL, PO and PPO) and PR proteins (chitinase and glucanase) were recorded highest in T7 (Seed treatment with promising endophytic bacterial consortium @ 4g/kg + seedling dip with promising endophytic bacterial consortium @ 4g/l at 15DAS + foliar application with promising endophytic bacterial consortium @ 250g/ha at 30DAT) and challenge inoculated with BLB pathogen.