Toxigenic potential of Fusarium species isolated from non-harvested maize.

The objective of this study was to determine the frequencies of distribution and the toxigenic potential of Fusarium species isolated from non-harvested maize left in field over winter in 1999 (N = 56) and 2003 (N = 56) in northern Croatia. Zearalenone and trichothecenes (DON, DAS, T-2) were isolated and detected using multitoxin extraction and TLC method. Modified TLC method was applied to detect fumonisin B1. Fusarium species were the most frequent fungi found in maize with 78.6% in 1999 and 85.0% in 2003. Among fusaria F. verticillioides was dominant species found in 12.5% (1999) and 35.7% (2003) of maize samples. Other determined fusaria were F. graminearum (8.9% in 2003), F. poae and F. sporotrichoides (2.0% to 3.6%), F. tricinctum and F. tabacinum (2.0% in 1999). Production of FB1 was established for all F. verticillioides (7/7) isolated in 1999 in concentration range from 280 mg L(-1) to 918 mg L(-1), and for 11 of 20 strains found in 2003 (48 mg L(-1) to 400 mg L(-1)). Three strains also produced zearalenone: one strain in 1999 produced 3.80 mg L(-1) and 2 strains in 2003 produced 20.0 mg L(-1) and 70.0 mg L(-1). In addition, four strains of F. graminearum isolated in 2003 produced higher amounts of zearalenone (60.0 mg L(-1) to 180.0 mg L(-1)). T-2 production was found in F. tricinctum (1.55 mg L(-1)) isolated in 1999.