Fitness Cost of Aflatoxin Production in Aspergillus flavus When Competing with Soil Microbes Could Maintain Balancing Selection.

Selective forces that maintain the polymorphism for aflatoxigenic and nonaflatoxigenic individuals of are largely unknown. As soils are widely considered the natural habitat of , we hypothesized that aflatoxin production would confer a fitness advantage in the soil environment. To test this hypothesis, we used DNA quantified by quantitative PCR (qPCR) as a proxy for fitness of aflatoxigenic and nonaflatoxigenic field isolates grown in soil microcosms.