Fusarium graminearum is one of the most important causes of FHB or wheat scab in different part of the world. This fungus is able to produce widespread Trichothecene mycotoxins such as Nivalenol (NIV) and Deoxynivalenol (DON) which are harmful for both human and animals. To determine chemotypes of Trichothecene, a total of 100 isolates from different fields of Golestan province in Iran including Gorgan, Kordkuy, Bandaregaz, Gonbad, Minodasht, Kalaleh and Azadshahr were identified as F. graminearum using morphological features then 96 isolates were confirmed by polymerase chain reaction (PCR) assay using F. graminearum species-specific primers (Fg16F/Fg16R). Based on sequences of Tri13 gene involved in the mycotoxin biosynthetic pathway, PCR assays was used to detect Nivalenol (NIV) and Deoxynivalenol (DON) chemotypes. Of the 96 tested isolates with Tri13 PCR assays, 70 classified as NIV chemotype and the remaining 26 isolates as DON producers. These results indicated that NIV chemotype was the most dominant chemotype in studied zones. A greater proportion of NIV chemotype was found in Gorgan fields (P < 0.05, P < 0.0001), whereas greater proportion of DON was detected in Gorgan and Gonbad fields (P < 0.05, P < 0.0001). Chemotyping by PCR assay were confirmed using HPLC method. These results demonstrated that PCR assay and HPLC could be used as rapid, reliable and cost-effective methods for the detection and identification of mycotoxin-producing Fusarium-species and may thus help to develop strategies to avoid or reduce mycotoxin contamination of cereals.  

Keywords: Fusarium graminearum, trichothecene, chemotypes, NIV, DON

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