Research Projects

Pigeonpea productivity in India has stagnated across major growing regions due to several challenges, including emerging soil-borne pathogens such as Fusarium wilt and dry root rot, declining soil fertility, and the unpredictable effects of climate change. These issues are further compounded by breeding practices that have primarily focused on increasing yields and enhancing disease resistance while neglecting the role of rhizosphere microbiome diversity. The rhizosphere microbiome in the root zone is essential for soil nutrient cycling, pathogen suppression, and overall plant health. The decline in microbiome diversity threatens pigeonpea resilience and risks cultivars losing resistance to emerging stains of pathogens, putting farmers at risk and making it difficult to meet increasing domestic demand. This research aims to address these challenges by exploring plant-microbe interactions, particularly the role of pigeonpea root exudates in shaping the microbial communities, to develop sustainable solutions that reduce crop losses, improve soil health, and enhance food security. The project seeks to investigate the variations in root exudate composition across diverse pigeonpea cultivars and their influence on rhizosphere microbial communities to recruit beneficial microbes around the root zone. It hypothesizes that differences in root exudate composition among pigeonpea cultivars significantly impacts the recruitment of beneficial microbes, including nitrogen-fixing, phosphorus-solubilizing, carbon-sequestering, and pathogen-suppressing microorganisms. Rhizosphere microbial communities manipulated by plant genetics, and their interactions are expected to promote soil biogeochemical properties, supress harmful microbes in the soil, and promote plant growth and enhance pigeonpea reliance under both biotic and abiotic stress conditions. The proposed work includes testing of diverse Fusarium wilt resistance and susceptible pigeonpea cultivars under sick field conditions and analyse their root exudate composition using LC-MS, focusing on identifying compounds linked to pathogen suppression, and to evaluate their inhibitory effects on pigeonpea soil-borne pathogens under in vitro conditions. Rhizosphere microbiomes will be profiled using high-throughput DNA sequencing to map the microbial communities associated with pathogen resistance and soil health. Functional assays will be conducted to study the interactions between specific root exudates and beneficial microbes. Insights from these experiments will guide breeding strategies for pigeonpea cultivars that can recruit and sustain robust microbiome associations. By achieving these objectives, the research will advance the fundamental understanding of plant-microbiome interactions to develop climate resilient pigeonpea varieties to support sustainable agricultural practices for improving yield, soil fertility, sustaining soil biodiversity and potential to reduce India’s reliance on pulse imports.