Management of aflatoxin through drought stress phenotyping, Aspergillus section Flavi characterization and accurate quantification of Aspergillus and aflatoxin contamination

Abstract

Aflatoxin is a major concern in peanut production especially in areas experiencing drought and high temperatures. The best way to manage aflatoxin contamination would be to integrate host resistance, identification of causal organism, and develop improved management strategies. Phenotyping of seven peanut genotypes identified Tifguard and Tifrunner as having better drought-coping ability than the other genotypes. Aspergillus section Flavi isolates collected from different geographical locations were identified through morphological and genetic variation. Evaluation of the effect of sample size in aflatoxin extraction demonstrated that the standard subsampling of 300 g into 100 g can be reduced to subsampling 100 g into 25 g. Immunochromatographic test strips were confirmed to have comparable aflatoxin detection results with fluorometry method and can be used under continuous high or fluctuating temperatures. Also, a real-time PCR (qPCR) assay using species-specific primers targeting the aflS gene effectively detected A. flavus and/or A. parasiticus in peanut seeds.