Evaluation of deoxynivalenol and virulence in dsRNA containing Fusarium graminearum Isolates

Double–stranded RNA (dsRNA) viruses in some fungi are associated with hypovirulence and have been used or proposed as biological control
agents. To determine the effect of dsRNA on pathogenicity and deoxynivalenol (DON) production by Fusarium graminearum isolates, the causal agent of
wheat head blight, three dsRNA–containing and dsRNA–free isolates were screened in this survey. Between the two groups, the disease severity of the
dsRNA-containing isolates, however, was significantly (p<0.01) less than that of the dsRNA–free isolates on susceptible wheat (cv. Falat) in a greenhouse
experiment. DON production by dsRNA–free and dsRNA-containing isolates of F. graminearum was confirmed using HPLC techniques. The range of in
vitro DON production levels varied from 0.07 to 1.62 ppm, and 0.06 to 0.4 ppm, respectively. A significantly reduced level of DON up to 50% was detected
in dsRNA-containing derivatives than the dsRNA–free isolates. Meanwhile, the range of DON production levels in spikes inoculated with dsRNA–free and
dsRNA-containing F. graminearum isolates varied from 0.56 to 0.9 ppm and 0.37 to 0.63 ppm, respectively. These results indicated 27.5% reduction in
DON production.

Evaluation of deoxynivalenol and virulence in dsRNA containing Fusarium graminearum Isolates

Said Abbas1, Aminian Parisa2, Alizadeh Azizollah2, Safaie Naser2