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

摘要

Effective biological control of aflatoxin-producing 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 B-1 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.