Evaluation of deoxynivalenol and virulence in dsRNA containing Fusarium graminearum Isolates

Abstract

Hypovirulence and the presence of double-stranded RNA (dsRNA) viruses in some fungus have led to
their potential use as biological control agents. This study screened three dsRNA-containing and one
dsRNA-free strain of Fusarium graminearum, the causative agent of wheat head blight, to assess the
influence of dsRNA on pathogenicity and deoxynivalenol (DON) synthesis. In a greenhouse experiment,
sensitive wheat (cv. Falat) was seen to have a considerably lower disease severity (p<0.01) when exposed
to the dsRNA-containing isolates compared to the dsRNA-free isolates. HPLC methods validated DON
synthesis by F. graminearum isolates with and without dsRNA. A range of 0.07 to 1.62 ppm and 0.06 to
0.4 ppm was observed for in vitro DON formation, respectively. In comparison to the dsRNA-free
isolates, dsRNA-containing derivatives showed a 50% reduction in DON. In the meanwhile, spikes
infected with F. graminearum isolates containing dsRNA ranged from 0.37 to 0.63 ppm, whereas spikes
injected with dsRNA-free varied from 0.56 to 0.9 ppm. According to these findings, the generation of
DON was reduced by 27.5%.