Fumonisin B1-4-producing capacity of Hungarian Fusarium verticillioides isolates

The fumonisin B1-4 (FB1-4) toxin-producing capacities of 60 strains of Fusarium verticillioides isolated in the main maize-cultivating areas of Hungary were screened on rice grains in vitro. The amounts of FB1, FB2, FB3 and FB4 in the extracts of the culture material were determined by RP-HPLC/ESI-IT MS without any sample clean-up. All F. verticillioides strains produced all analogues (FB1-4) of the fumonisin B series. The strains did not differ significantly in their cultural characteristics, though the analytical results allowed the distinction of three idiosyncratic FB1-4-producing chemotypes with characteristic proportions of the fumonisin B analogues. The dominant chemotype produced them in the sequence FB1 > FB2 > FB3 > FB4, with large amounts of FB1 and FB2. A second chemotype produced a higher amount of FB3 than of FB2, while the third chemotype produced large amounts of FB2 and FB4. The proportion of FB1 in the extracts was inversely correlated with the total FB yield. No differences in FB1-4 producing capacity were observed between strains isolated from various locations or different sources.