TOXICITY AND OCCURRENCE OF FUSARIUM SPECIES AND MYCOTOXINS IN LATE HARVESTED AND OVERWINTERED GRAIN FROM NORWAY, 1993

Samples of grain, harvested in October/November of 1993 or in the spri ng of 1994 from fields in Norway with overwintered grain, were collect ed. The presence of Fusarium species and the amount of mycotoxins prod uced by this genus were determined. The cytotoxic properties of the gr ain samples were examined with an in vitro methylthiazoltetrazolium (M TT)-cell culture assay using swine kidney and VERO cells as target cel ls. The total count of colony forming units of Fusarium species was ab out the same in the grain harvested in late autumn and in the spring, but the dominant species seemed to vary somewhat between the two group s. F. culmorum was found more in the samples from October/November whi le F. avenaceum was isolated more in the grain harvested in the spring . Only small amounts of F. sporotrichioides were present in the grain harvested in the autumn, and none was found in the overwintered grain. The deoxynivalenol content was significantly higher in the grain harv ested in autumn than in the overwintered grain. Although very small am ounts of toxins were detected in the overwintered grain, it was more c ytotoxic than the grain harvested in October/November. A significant c orrelation between the cytotoxicity and the amount of F. avenaceum in the samples was found.