Fusarium awaxy associated with maize from Paraguay : a first report

Abstract

Maize (Zea mays L.) is a cornerstone of food security and livestock production in Paraguay. However, its productivity and grain safety are increasingly threatened by Fusarium species because of their pathogenic capacity and ability to produce mycotoxins. In this study, symptomatic maize leaves collected from commercial fields in Pirapó, Itapúa, during the 2022 growing season were processed to isolate and characterize fungal pathogens. Three isolates displaying typical Fusarium morphology were obtained and examined through macroscopic and microscopic traits. Molecular identification was conducted using translation elongation factor 1-α 1-α (TEF) sequences, followed by phylogenetic inference using maximum likelihood and Bayesian methods. The Paraguayan isolates (PYF-MZE22-01, -02, -03) clustered with the ex-type strain Fusarium awaxy CBS139380 in a strongly supported clade, confirming species identity. This finding constitutes the first record of F. awaxy associated with maize in Paraguay, thereby expanding its known geographical distribution. Considering that members of the Fusarium fujikuroi species complex are recognized producers of regulated mycotoxins, the detection of F. awaxy raises concerns regarding its pathogenic potential and possible implications for food safety. These results underscore the importance of integrating molecular diagnostics, toxigenic profiling, and surveillance programs to monitor emerging Fusarium taxa in South American agroecosystems.