Molecular Identification of Fusarium spp. Isolated from Wheat Grain Based on Sequencing of Internal Transcribed Spacer (ITS) Region

Molecular identification via Internal Transcribed Spacer region (nrDNA-ITS) sequencing of Fusari¬um spp. isolates from wheat grain originated from Stara Zagora region was performed for the first time in Bulgaria. А total of 60 wheat grain samples (Triticum aestivum) were preliminarily morphologically iden¬tified at the genus level as Fusarium spp. The rDNA-ITS region of all isolates was successfully amplified and the PCR products obtained were directly sequenced. After a comparison of detected sequences with the NCBI database, members of three different fungal genera (Fusarium, Chaetomium and Alternaria) were identified. Among the Fusarium isolates, F. tricinctum was prevailing, followed by F. poae. A total of three isolates, F. proliferatum, F. graminearum and F. equiseti, were presented with a single probe. The shortest genetic distance (0.004) was detected between F. tricinctum isolates. On the basis of genetic distances, fun¬gal isolates were grouped into two main clusters – one comprising F. tricinctum isolates and F. proliferatum, and the second including F. equiseti, F. graminearum and F. poae. It could be concluded that the rDNA-ITS genome region of the genus Fusarium may be used as a suitable marker for early detection, accurate and reliable identification of Fusarium spp. contamination of wheat. The timely and accurate information would assist in the selection of appropriate approaches for control of Fusarium infections and possible mycotoxin contamination of agricultural products.