TRICHOTHECENE CHEMOTYPES OF 3 FUSARIUM SPECIES

Identification of the mycotoxins produced by different species of Fusarium can serve to verify their classification or to relate the variation of toxigenic potential within a species. Strains of Fusarium graminearum (55), Fusarium crookwellense (16), and Fusarium culmorum (3) were grown in three liquid media and on rice. The toxins produced in the various media were assessed by analyzing the metabolites by gas chromatography/mass spectrometry. These data are used to propose a number of chemotypes. The metabolic profiles of Fusarium graminearum were similar, having chemotype I (deoxynivalenol) in common. In Chinese strains, chemotype IA (deoxynivalenol, 3-acetyl) predominated while the Mexican strains, as with other North American strains, were chemotype IB (deoxynivalenol, 15-acetyl). The Fusarium culmorum strains tested had a chemotype similar to that of chemotype IA of Fusarium graminearum. The Fusarium crookwellense strains, which were collected from eight countries, had a chemotype II (nivalenol, diacetyl) in common, regardless of their source. A similar chemotype II has been reported for Fusarium graminearum strains but it is rare. The Fusarium crookwellense strains also showed the presence of chemotype IA (isotrichodermin, 8-hydroxy) and chemotype IB (isotrichodermin, 7-hydroxy).