Sclerotia Formation and Toxin Production in Large Sclerotial <i>Aspergillus flavus</i> Isolates from Kenya

We studied the relationship between sclerotia formation and aflatoxin productionby Aspergillusflavus strains isolatedfrom maize kernels from Nandi County. Isolates recovered from maize kernels weretested for their ability to form sclerotia on different growth media. PCR analysiswas done on the isolates to detect 2 structural genes, aflD and aflQ, involved inaflatoxin biosynthesis pathway. Positive A.flavus isolates for one or both genes were grown on Yeast Extract Sucrose Agarmedium and aflatoxins quantified using LCMSMS. All the isolates formed large sclerotiaand their formation was influenced by media type but could not be related to amountof aflatoxins produced both in vivo and in vitro. Though sclerotia areperennating structures and so contribute to survival index of a fungus, their initiationis regulated by external factors though ability to form is genetic. This bringsambiguity of their presence or abundance as a measure of toxicity.