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Gibberella zeae (anamorph Fusarium graminearum) causes Fusarium head blight of wheat. The authors used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of two G. zeae populations from commercial wheat fields. The working hypothesis was that sufficient genetic exchange occurs between local populations to prevent significant partitioning of allelic variation. We analysed 216 AFLP loci for 113 isolates collected during the 2002 harvest season. All strains had AFLP profiles typical of G. zeae lineage 7. Both populations were genotypically diverse but genetically similar and potentially part of a larger, randomly mating population, with significant genetic exchange probably occurring between the two subpopulations. Linkage disequilibrium was low, but higher than reported for many other populations of G. zeae, and about 20% of the alleles detected were specific to one of the two subpopulations - results consistent with limited gene exchange between the two subpopulations. This study extends previous work with populations of G. zeae to include those found in Argentina, one of the world's largest wheat growing countries.

The Aspergillus flavus population was evaluated in the period 1998-2001 in soil samples from the peanut-growing region in Argentina. A total of 369 A flavus isolates were examined for sclerotia, aflatoxin and cyclopiazonic acid production. The L phenotype was isolated in a higher percentage than the S phenotype and represented 59% of the total isolates. Statistical analysis showed significant differences between L, S and non-sclerotial strains with regard to aflatoxin and cyclopiazonic acid production (p < 0.05). The S strains produced higher mycotoxin levels than the L and non-sclerotial strains. About 10% of the S strains had an unusual pattern of mycotoxin production because they simultaneously produce aflatoxins B and G and CPA. The S BG strains isolated in the present study have all morphological and microscopic characteristics of A flavus. These strains are of concern in food safety, as there is a higher probability of aflatoxin contamination in peanuts.

The aim of this study was to evaluate the occurrence of several fungal metabolites, including mycotoxins in natural grasses (Poaceae) intended for grazing cattle. A total number of 72 and 77 different metabolites were detected on 106 and 69 grass samples collected during 2011 and 2014, respectively. A total of 60 metabolites were found across both years. Among the few mycotoxins considered toxic for ruminants, no samples of natural grasses were contaminated with aflatoxins, ochratoxin A, ergot alkaloids, and gliotoxin, among others. However, we were able to detect important metabolites (toxic to ruminants) such as type A trichothecenes, mainly T-2 toxin and HT-2 toxin (up to 5000 µg/kg each), and zearalenone (up to 2000 µg/kg), all at very high frequencies and levels. Other fungal metabolites that were found to be prevalent were other Fusarium metabolites like beauvericin, equisetin and aurofusarin, metabolites produced by Alternaria spp., sterigmatocystin and its precursors and anthrachinone derivatives. It is important to point out that the profile of common metabolites was shared during both years of sampling, and also that the occurrence of important metabolites is not a sporadic event. Considering that this area of temperate grassland is used for grazing cattle all year long due to the richness in palatable grasses (Poaceae), the present work represents a starting point for further studies on the occurrence of multi-mycotoxins in natural grasses in order to have a complete picture of the extent of cattle exposure. Also, the present study shows that the presence of zeranol in urine of beef cattle may not be a consequence of illegal use of this banned substance, but the product of the natural occurrence of zearalenone and α-zearalenol in natural grasses intended for cattle feeding.

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With 744 million metric tons produced in 2017/2018, bread wheat (Triticum aestivum) and durum wheat (Triticum durum) are the second most widely produced cereal on a global basis. Prevention or control of wheat diseases may have an enormous impact on global food security and safety. Fusarium head blight is an economically debilitating disease of wheat that reduces the quantity and quality of grain harvested, and may lead to contamination with the mycotoxin deoxynivalenol, which affects the health of humans and domesticated animals. Current climate change scenarios predict an increase in the number of epidemics caused by this disease. Multiple strategies are available for managing the disease including cultural practices, planting less-susceptible cultivars, crop rotation, and chemical and biological controls. None of these strategies, however, is completely effective by itself, and an integrated approach incorporating multiple controls simultaneously is the only effective strategy to limit the disease and reduce deoxynivalenol contamination in human food and animal feed chains. This review identifies the available tools and strategies for mitigating the damage that can result from Fusarium head blight.