Fumonisin production by Fusarium species isolated from freshly harvested corn in Iran

Fifty-one strains of Fusarium verticillioides and F. proliferatum isolated from corn collected from four different geographic areas in Iran, namely Fars, Khuzestan, Kermanshah and Mazandaran (an endemic oesophageal cancer (OC) area) were evaluated for their ability to produce fumonisins B-1 (FB1), B-2 (FB2) and B-3 (FB3) in corn culture. Fumonisin levels were determined by high-performance liquid chromatography. All tested strains of F. verticillioides and F. proliferatum produced fumonisins within a wide range of concentrations, 197-9661 mug/g, 18-1974 mug/g, and 21-1725 mug/g for FB1, FB2, and FB3, respectively. The highest mean concentrations of FB1, FB2, and FB3 were 3897, 806 and 827 mug/g, respectively. Overall, 61% of the F. verticillioides and F. proliferatum strains produced higher levels of FB3 than FB2. The mean ratios of FB1: FB2, FB1: FB3 and FB1: total fumonisins were 8, 7 and 0.7 for F. verticillioides and 5.7, 10.7 and 0.7 for F. proliferatum, respectively. Significant differences in some of the meteorological data ( rainfall, relative humidity and minimum temperature) from the four provinces were observed. Fumonisin levels produced by F. verticillioides strains isolated from Khuzestan province (tropical zone) were significantly (P < 0.01) higher than the other three provinces. This is the first report of the fumonisin-producing ability of F. verticillioides and F. proliferatum strains isolated from corn harvested from different geographic areas in Iran.