Variability of the Fusarium graminearum species: Pathogens of small grains in Serbia

Species of the genus Fusarium are predominant pathogens in cereals worldwide, while F. graminearum is the most distributed among them. This species synthesises a broad spectrum of mycotoxins (fusariotoxins), among which, trichothecene type B (deoxynivalenol-DON) and zearalenone (ZEA) prevail. The isolates from the collection of the Laboratory of Phytopathology of the Maize Research Institute, Zemun Polje were used to study diversity of the F. graminearum species. Twelve selected isolates were collected in the 2005-2016 period from wheat and barley kernels in various locations in Serbia. The aim of this study was to observe variability of the F. graminearum species regarding isolate pathogenicity, mycelium growth, macroconidium size, as well as DON and ZEA production potential by the ELISA method. All the observed isolates indicated pathogenic potential in the field and expressed different viability ranging from 1.75 to 3.75. Besides different viability, microscopic and macroscopic properties of isolates also diverged. The isolates of F. graminearum produced average concentrations of DON amounting 119. 9 and 33.4 ug/g (isolates from wheat and barley, respectively), while the average concentration of ZEA was 40.14 ug/kg (isolates from wheat) and 31.25 ug/kg (isolates from barley). A correlation between production of DON and ZEA was not observed in the isolates of F. graminearum.