Relationship of drought tolerance traits with aflatoxin contamination in groundnut

Fifty groundnut (Arachishypogaea L.) genotypes were screened for low aflatoxin contamination under field conditions with two main treatments i.e., irrigated and simulated drought conditions. A severe strain of A.flavus was isolated by collecting native strains from different parts of Chittoor district in Andhra Pradesh and a sick plot was developed utilizing this strain. A.flavus inoculum was applied @ 2.5 g per meter row length and sufficient spore load was maintained till harvest. Mean aflatoxin contentwas higher under imposed moisture stress conditions compared to irrigated treatment. The genotypes differed in tolerance to aflatoxin in irrigated and simulated drought conditions. Among the fifty groundnut genotypes screened ICGV 86590, 89104, 94350, 99029, IC 48 and ICGS 76 had low aflatoxin levels (< 5 ppb) in both irrigated and simulated drought treatments. No consistent relationship was observed between seed colonization and aflatoxin production. The results indicate that aflatoxin production in groundnut is negatively related with relative water content (RWC), pod wall integrity and pod wall moisture content at harvest.