Incidence and toxigenicity of fungi contaminating sorghum from Nigeria

Abstract

Each Agro-ecological zone was transversely delineated into 5districts and five villages (at least 20 Km from each other) called “locations” were selected in each district. In each district, Sorghum grains in stores, bunches in the field and sorghum grains in the market were sampled from five locations, each approximately 20 km from the previous sampling location. The mycological analytical procedures were performed under aseptic condition. Plates were counted for fungal colonies using a colony counter and the number of fungal colonies per gram of sample was calculated as CFU/g. The fungi species were isolated and subsequently identified using MEA/CYA media for Aspergillus and Penicillium species and PDA for the fusarium species Toxigenicity studies on strains representing species of Aspergillus, Penicillium, Fusarium was carried out to determine their ability to produce aflatoxin B1 (AFB1); aflatoxin B2 (AFB2); aflatoxin G1 (AFG1); aflatoxin G2 (AFG2); OTA, ZEN, DON and FB1. A total of 701 isolates were recorded which consist of 67 confirmed fungal strains. Aspergillus species formed the majority with 346(49.6%) followed by the Fusarium species with 186(26.7%) then Penicillium species with 102(14.6%) while others such as Cuvularia, Phoma, Alternaria, Rhizormucor constitutes 67 (9.0% )strains of the total population.