PRODUCTION OF MYCOTOXINS BY SELECTED FUSARIUM-GRAMINEARUM AND F-CROOKWELLENSE ISOLATES

Corn cultures (five isolates each of Fusarium graminearum Group 1 from wheat crowns, Group 2 from scabby wheat grains and from ear rot of corn and five isolates of F. crookwellense) were screened for their ability to produce deoxynivalenol (DON), nivalenol (NIV), fusarenon-x (FUS-X) and zearalenone (ZEA). Nine of the ten F. graminearum isolates from wheat produced DON (5-165-mu-g g-1) but none produced either NIV or FUS-X. Conversely, 3/5 and 2/5 of the F. graminearum isolates from corn produced NIV (5-40-mu-g g-1) and FUS-X (5-7-mu-g g-1), respectively, while none produced DON. All but one of the F. graminearum isolates produced ZEA (2-1160-mu-g g-1). None of the F. crookwellense isolates produced DON, but 5/5 and 4/5 produced NIV (6-170-mu-g g-1) and FUS-X (3-90-mu-g g-1), respectively, and all produced ZEA (605-1030-mu-g g-1). The results confirmed previous findings on the presence of two distinct F. graminearum chemotypes.