Survey of Freshly Harvested Oat Grains from Southern Brazil Reveals High Incidence of Type B Trichothecenes and Associated Fusarium Species

The current study investigated the fungal diversity in freshly harvested oat samples from the two largest production regions in Brazil, Paraná (PR) and Rio Grande do Sul (RS), focusing primarily on the genus and the presence of type B trichothecenes. The majority of the isolates belonged to the species complex, and were identified as sensu stricto (s.s.), , and . In the RS region, was the most frequent fungus, while s.s. was the most frequent in the PR region. The s.s. isolates were 15-ADON genotype, while and were NIV genotype. Mycotoxin analysis revealed that 92% and 100% of the samples from PR and RS were contaminated with type B trichothecenes, respectively. Oat grains from PR were predominantly contaminated with DON, whereas NIV was predominant in oats from RS. Twenty-four percent of the samples were contaminated with DON at levels higher than Brazilian regulations. Co-contamination of DON, its derivatives, and NIV was observed in 84% and 57.7% of the samples from PR and RS, respectively. The results provide new information on contamination in Brazilian oats, highlighting the importance of further studies on mycotoxins.