Molecular versus Morphological Identification of Fusarium spp. isolated from Egyptian corn

Fumonisins are important mycotoxins produced mainly by Fusarium verticillioides and Fusarium proliferatum, which are associated with human esophageal cancer. In this study, 56 Fusarium isolates -from 31 field maize samples collected from Egypt, were identified using both morphological and molecular methods. The potential production of fumonisin B1 was determined using HPLC and molecular methods. The results of molecular identification showed that all Fusarium isolates belonged to F. verticillioides, based on F. verticillioides-specific primer pair Verpro-F/VERTI-R and primer pair Taqfum-2f/Vpgen-3R, which is specific for F. verticillioides, F. proliferatum, F. subglutinans, F. globosum and F. nygamai, while the morphological and microscopic identification of the 56 isolates showed that 54 isolates (96.4%) belonged to F. verticillioides, 1 isolate (1.8%) belonged to F. proliferatum and 1 isolate (1.8%) belonged to F. subglutinans; showing compatibility of 96.4% with the molecular identification. Although just one corn sample from the 31 contained 9.8 mg kg-1 FB1; which considered higher than the permissible limit (3 mg kg-1). The HPLC analysis confirmed that about 82% of the isolates were able to produce fumonisin B1 in ranges between 1.4 to 555 mgkg-1 medium. Whereas, PCR detection indicated that all isolates were able to produce fumonisin B1. Results of this study revealed that PCR-based technique could be used to differentiate the Fusarium species from other genera of fungi as well as to identify fumonisin-producing Fusarium species.