Molecular identification and detection of gene encoding deoxynivalenol in Fusarium graminearum isolates, the causal agent of fusarium head blight of wheat in Iran

Fusarium Head Blight (FHB) is one of the most important fungal diseases of wheat in Iran and throughout the world. Fusarium species infect wheat during the flowering period. In addition to losses of yield, these fungi can also synthesize mycotoxins under suitable environmental conditions, thus threatening animal and human health. In the present study, 60 isolates of F. graminearum collected from infested wheat fields of some provinces of Iran and were characterized morphologically and genetically. Molecular characterization of isolates was performed using an optimized simple and low cost method for isolation of DNA from F. graminearum using polymerase chain reaction with species specific primers. All of the isolates were confirmed as F. graminearum using species specific primers Fg16F/Fg16R through PCR assays. The results indicated that a specific band of 420 bp was amplified, when species specific primers of F. graminearum was used. All of the isolates were molecularly identified as F. graminearum. The primers failed to amplify any band in negative controls including F. culmorum. All of F. graminearum isolates were tested for DON chemotype producing gene by specific Tri13F/Tri13DONR primer by PCR. Our results showed that a specific band of 282 bp was amplified only in 36 isolates (60%). Consequently, using of species specific primers for detection of suspected cultures of F. graminearum in infected tissues and toxin profile of isolates are very interesting when comparing with the morphological trait which are time consuming and non-specific.