OCCURRENCE AND TOXIGENICITY OF FUSARIUM-PROLIFERATUM FROM PREHARVEST MAIZE EAR ROT, AND ASSOCIATED MYCOTOXINS, IN ITALY

Forty-two samples of preharvest maize ear rot, collected in 1992-1993 from different maize fields throughout Italy, were examined for the relative incidence of Fusarium proliferatum and its toxigenicity. F. proliferatum (34%), together with F. moniliforme (54%), were the predominant species in infected ear kernels. Less frequently isolated were F. equiseti(8%) and F. graminearum (2%), and to a much lesser extent, F. chlamydosporum, F. culmorum. F. oxysporum, F. semitectum, F. solani, F. sporotrichioides, and F. subglutinans. When cultured on autoclaved maize kernels for 4 wk in the dark at 25 C, mycotoxin production by strains of F. proliferatum was as follows: all of the 26 assayed strains (100%) produced fumonisin B-1 (up to 2,250 mg/kg); 22 strains (85%) also produced beauvericin (up to 200 mg/kg); and 12(46%) produced fumonisin B-1, beauvericin, and moniliformin (up to 5,300 mg/kg). Cultural extracts of almost all F. proliferatum strains revealed a high level of toxicity towards Artemia salina larvae. Selected infected maize ears, mostly colonized by F. proliferatum, were found to be contaminated by fumonisin B-1 (up to 250 mg/kg), beauvericin (up to 40 mg/kg), and moniliformin (200 mg/kg). This is the first investigation of the relative incidence of toxigenic F. proliferatum strains as causal agents of maize ear rot, as well as of the natural occurrence of mycotoxins in preharvest F. proliferatum-colonized maize ears. The results strongly suggest a more significant role of F. proliferatum in maize ear rot and in the associated mycotoxicoses. Moreover, these results show that a potential exists for the production of beauvericin, fumonisin B-1, and moniliformin in maize grown in Italy.