Production of Trichothecene Mycotoxins of Fusarium Species in Wheat and Barley Harvested in Saitama Prefecture

Freshly harvested wheat and barley of the 1977 crop were examined for trichothecene mycotoxins contamination and for the presence of Fusarium species.Trichothecenes such as deoxynivalenol, fusarenon-X, nivalenol, diacetoxyscirpenol, neosolaniol and T-2 toxin were not detected in these samples. The incidence of Fusarium contamination ranged from 0 to 32.7%.The most common species was F. graminearum; 73.7% of the total Fusarium isolates (810 strains) belonged to this species, followed by F. equiseti, F. oxysporum, F. semitectum and F. avenaceum (8.0%, 5.6%, 3.3% and 3.3%, respectively). Frequencies of F. tricinctum, F. poae, F. moniliforme, F. acuminatum, F. merismoides, F. solani and F. sulphureum were very low in these samples.The occurrence of trichothecene-producing strains in the 179 isolates selected was 43%. Among 57 isolates of F. graminearum, 43 produced both nivalenol and fusarenon-X, and 4 produced deoxynivalenol. Several trichothecenes, such as nivalenol, fusarenon-X, diacetoxyscirpenol and neosolaniol, were produced simultaneously by 16/25 isolates of F. equiseti and 8/23 isolates of F. semitectum. Three of 4 F. acuminatum produced both T-2 toxin and neosolaniol, and one of 5 F. poae also produced neosolaniol.