Beauvericin and fumonisin B1 in preharvest Fusarium moniliforme maize ear rot in Sardinia.

Six selected samples of preharvest maize ear rot, from different localities in Sardinia, Italy, were examined for causal Fusarium species and associated mycotoxins. All samples were almost exclusively found to be affected by Fusarium moniliforme, which was isolated from all infected ear sample kernels (100%). In two samples, in addition to F. moniliforme, F. proliferatum was also present but in a reduced percentage of kernels (up to 42%). All samples were found to be contaminated by fumonisin B1 (up to 250 mg/kg). Four samples were also found to be contaminated by beauvericin (up to 10 mg/kg), with higher concentration in samples also infected by F. proliferatum. When cultured on autoclaved maize kernels for 4 weeks at 25 degrees C, all 13 strains of F. moniliforme examined produced fumonisin B1 (up to 3750 mg/kg), whereas only three strains also produced beauvericin, but in very low amounts (5 mg/kg). In the same assay, four isolates of F. proliferatum also produced high amounts of fumonisin B1 (up to 2500 mg/kg) but this was associated with higher concentrations of beauvericin (up to 175 mg/kg). This is the first indication of the production of beauvericin by F. moniliforme, as well as of its co-occurrence with fumonisin B1 in preharvest F. moniliforme maize ear rot.