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Poster: Biology & Disease Mgmt: Postharvest Pathology & Mycotoxins


Diversity of aflatoxin producing fungi in Malawi
C. CHING'ANDA (1), J. Atehnkeng (2), R. Bandyopadhyay (3), P. Cotty (4) (1) University of Arizona, U.S.A.; (2) International Institute of Tropical Agriculture (IITA), Malawi; (3) International Institute of Tropical Agriculture (IITA), Nigeria; (4) USDA-AR

Aflatoxins are toxic fungal metabolites that often contaminate Malawi’s food and feed. These toxins cause immune suppression, stunting, and cancer. Aspergillus flavus and A. parasiticus are the most frequently reported causes of contamination. Aflatoxin producers vary widely in genetic diversity, aflatoxin production, and agro-ecological preference. Little is known about the diversity of fungi causing aflatoxin contamination in Malawi. The current study examined DNA variability among aflatoxin producers in Malawi. Maize and groundnuts were sampled across the five agro-ecological zones of Malawi and fungi infecting crops and belonging to Aspergillus section Flavi were identified. The A. flavus L morphotype comprised 44% of the infecting fungi. Fungi with S morphology composed 40% and A. parasiticus made up 15%. Use of molecular phylogenetics to assign S morphology fungi to species is underway. Fungi that did not produce aflatoxins (793) and belonged to the A. flavus L morphotype were characterized at 17 microsatellite loci in order to identify fungi of potential value as biocontrol agents for the aflatoxin prevention. 350 microsatellite haplotypes were detected. Knowledge of variability among the aflatoxin producers may also provide opportunity to improve aflatoxin management.