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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #330581

Research Project: Improved Environmental and Crop Safety by Modification of the Aspergillus flavus Population Structure

Location: Pest Management and Biocontrol Research

Title: Atoxigenic Aspergillus flavus endemic to Italy for biocontrol of aflatoxins in maize

item MAURO, ANTONIO - Institute Of Entomology And Plant Pathology
item BATTILANI, PAOLA - Institute Of Entomology And Plant Pathology
item Cotty, Peter

Submitted to: BioControl
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2014
Publication Date: 10/5/2015
Citation: Mauro, A., Battilani, P., Cotty, P.J. 2015. Atoxigenic Aspergillus flavus endemic to Italy for biocontrol of aflatoxins in maize. Biocontrol. 60:125-134.

Interpretive Summary: Aflatoxins are toxic fungal metabolites that impair the immune system and cause cancer in humans. These poisons are produced by a diverse group of fungi. The most effective management tools for limiting contamination are biocontrol products utilizing native strains of Aspergillus flavus to displace aflatoxin-producing fungi. Aflatoxin contamination of maize has been a problem in Italy over the past decade and has had negative effects on the cheese industry. There is a desire in Italy to have biocontrols like those available in the US for use in Italy. In order to develop aflatoxin biocontrol products based on atoxigenic strains of A. flavus native to Italy we examined the fungi associated with aflatoxin contamination of maize in Italy and selected atoxigenic strains that were well adapted to Italy and also had the ability to prevent aflatoxin contamination on maize in vitro. During the process several genetic groups of A. flavus of potential value as biological control agents were also discovered. This work resulted in identification of atoxigenic strains of A. flavus that have already entered field evaluation for use as active-ingredients of products that prevent aflatoxin contamination in Italian maize.

Technical Abstract: Effective biological control of aflatoxin­producing Aspergillus flavus with atoxigenic members of that species requires suitable A. flavus well adapted to and resident in target agroecosystems. Eighteen atoxigenic isolates of A. flavus endemic in Italy were compared for ability to reduce aflatoxin contamination of maize in laboratory studies. Reduction in aflatoxin B1 concentrations ranged from 61 to 90% with the most effective five atoxigenics, belonging to five different vegetative compatibility groups, causing reductions similar to, or greater than, those achieved by an atoxigenic that is the active ingredient in a product registered in the USA for aflatoxin management. The atoxigenic isolates were effective against each of the six Italian aflatoxin-producers tested and both with equal proportions of toxigenic and atoxigenic isolates and when atoxigenic isolates were only inoculated at 25% the concentration of toxigenic. Equal proportions provided the highest percent reduction in contamination, but at the 4:1 ratio atoxigenics were the most efficient. The identified atoxigenic isolates will be of value as active ingredients in biocontrol products for reduction of aflatoxins in maize produced on the Italian Peninsula.