Effect of selected fungicides on the Fusarium growth and toxins production

We examine the effects of selected fungicides on the Fusarium growth and toxins production especially of DON and T-2 toxins. Appropriate nutritive media were prepared containing different concentrations of the fungicides tested (Horizon 250 EW and Falcon 460 EC), inoculated with Fusarium moulds, and incubated under various conditions. The extraction of Fusarium toxins and their determination were carried out after the incubation using Agra Quant®Deoxynivalenol Test kit and Agra Quant® T-2 toxin Test kit. The results indicated a considerable variability of the individual strains in the formation of toxins. The strains of Fusarium graminearum CCM F-683 and Fusarium spp. (isolated from wheat) produced large quantities of both DON and T-2 toxins. Fusarium poae CCM F-584 and Fusarium sporotrichioides CCM F-352 always produced larger quantities of only T-2 toxin in the given nutrient media. The experiment showed that the use of lower concentrations of fungicides resulted in an increased production of the monitored mycotoxins. The presence of Tri5 gene in the tested Fusarium strains, coding trichodiene synthase, was confirmed by polymerase chain reaction. The enzyme - trichodiene synthase - catalyses the isomerisation and cyclisation of farnesyl phosphate to trichodiene, the first step in the biosynthetic pathway of trichothecenes.