Natural Contamination with Mycotoxins Produced by Fusarium graminearum and Fusarium poae in Malting Barley in Argentina

Abstract

Two of the most common species of toxin-producing <i>Fusarium</i> contaminating small cereal grains are <i>Fusarium graminearum</i> and <i>F. poae</i>; with both elaborating diverse toxins, especially deoxynivalenol (DON) and nivalenol (NIV), respectively. The objective of our work during the 2012-2014 growing seasons was to screen crops for the most commonly isolated <i>Fusarium</i> species and to quantify DON and NIV toxins in natural malting-barley samples from different producing areas of Argentina. We identified 1180 <i>Fusarium</i> isolates in the 119 samples analyzed, with 51.2% being <i>F. graminearum</i>, 26.2% <i>F. poae</i> and 22.6% other species. We found high concentrations of mycotoxins, at maximum values of 12 μg/g of DON and 7.71 μg/g of NIV. Of the samples, 23% exhibited DON at an average of 2.36 μg/g, with 44% exceeding the maximum limits (average of 5.24 μg/g); 29% contained NIV at an average of 2.36 μg/g; 7% contained both DON and NIV; and 55% were without DON or NIV. Finally, we report the mycotoxin contamination of the grain samples produced by <i>F. graminearum</i> and <i>F. poae</i>, those being the most frequent <i>Fusarium</i> species present. We identified the main <i>Fusarium</i> species affecting natural malting-barley grains in Argentina and documented the presence of many samples with elevated concentrations of DON and NIV. To our knowledge, the investigation reported here was the first to quantify the contamination by <i>Fusarium</i> and its toxins in natural samples of malting barley in Argentina.