Research Projects

Rationale: Blast disease, caused by the fungus Magnaporthe oryzae, remains one of the most economically devastating diseases of rice, leading to significant yield losses globally. It also increasingly affects millets such as pearl millet and finger millet, crops vital to food security in dryland areas like Bundelkhand. While fungicides and resistant cultivars remain the primary tools for disease management, their effectiveness is diminishing due to pathogen evolution, resistance breakdown, and environmental concerns. There is a growing need for alternative, eco-friendly, and sustainable disease control methods. Microbiome research has revealed that plant-associated microbes play key roles in plant health, but little is known about the microbial succession that occurs directly on disease lesions, particularly in cereal crops. Blast lesions present a dynamic and unique microbial niche that may harbour bacterial species with potential biocontrol properties. Objectives: 1. To characterize the bacterial community succession associated with blast lesions caused by Magnaporthe in rice, pearl millet, barnyard millet and finger millet. 2. To isolate and identify culturable bacteria associated with blast-infected tissues. 3. To screen the isolated bacterial strains for antagonistic activity against Magnaporthe oryzae under in vitro and in vivo conditions. 4. To develop and validate a foliar microbial formulation composed of promising bacterial strains for the effective and sustainable management of blast disease. Hypothesis and Model to be Tested: The central hypothesis of the study is that blast lesions on cereals undergo a defined bacterial succession over time, and this niche harbours specialised bacterial populations adapted to suppress M. oryzae and/or activate host defenses. These lesion-associated microbes, if isolated and functionally screened, can serve as effective foliar biocontrol agents. The conceptual model integrates microbial ecology with plant pathology, proposing that the dynamic lesion microbiome can be mined for natural antagonists and used to develop a targeted microbial formulation for disease management. Main Experiments and Methodology: 1. Field Sampling: Blast-infected leaf samples will be collected from at different disease stages across multiple locations. 2. Microbiome Profiling via Amplicon Sequencing: 16S rRNA-based metagenomic analysis will be performed to understand bacterial succession over time in lesion tissues. Community diversity and structure will be analysed using QIIME2 and R. 3. Isolation and Characterization of Bacteria: Bacteria will be isolated from lesion tissues using culture-based methods and identified via 16S rRNA sequencing. Morphological and biochemical traits will be assessed. 4. Functional Screening for Antagonism: Isolates will be tested in vitro for antifungal activity (dual culture, VOCs, siderophores), and in vivo on cereal seedlings under greenhouse conditions. 5. Consortium Development and Formulation: Compatible, synergistic strains will be formulated into a foliar microbial product. 6. Field Evaluation: Microbial formulations will be tested under field conditions using a randomised block design to assess disease reduction, yield impact, and environmental safety. Estimated Significance: If successful, this research will have both fundamental and applied significance. Fundamentally, it will generate novel insights into the succession and ecology of bacterial communities associated with fungal lesions in cereals—an underexplored aspect of plant-microbe-pathogen interactions. The findings could redefine how microbial niches are targeted for biocontrol research and open new directions in microbiome-assisted plant protection. On the applied front, the development of a foliar microbial formulation could revolutionize blast management strategies. It will provide farmers with an affordable, sustainable, and chemical-free solution.