Production of the mycotoxins zearalenone, 4-deoxynivalenol and nivalenol by isolates of Fusarium graminearum groups 1 and 2 from cereals in Queensland

Abstract

The production of the mycotoxins zearalenone (ZEA), 4-deoxynivalenol (DON) and nivalenol (NIV) by isolates of Fusarium graminearum from different crops and regions in Queensland was examined in maize meal incubated for 28 days at 28¦C. Sixteen isolates of F. grarninearum Group 1 from wheat and barley stalks and a wheat seed in southern Queensland produced ZEA (range 208-2367, median 833 mg kg-1) and DON (range 3-28, median 15 mg Kg-1). One Group 1 isolate from a wheat stalk was unlike these 16, producing 2 mg ZEA kg-1 and 168 mg DON kg-1. Fifteen isolates of F. graminearum Group 2 from wheat seeds and spikelets, and sorghum and maize stalks in southern Queensland produced ZEA (range 25-2280, median 629 mg kg-1) and DON (range 11-904, median 200 mg kg-1. Three isolates from wheat seeds produced ZEA (range 5-41, median 15 mg kg-1) and NIV (range 10-75, median 40 mg kg-1). All 23 isolates of F. graminearum Group 2 from maize seeds and stalks in northern Queensland produced ZEA (range 3-228, median 40 mg kg-1) and NIV (range 8-270, median 26 mg kg-1). Group 1 isolates tended to produce more ZEA and less DON than Group 2 DON-producers, but there was a degree of overlap. Group 2 NIV-producers generally produced less ZEA than Group 1 and Group 2 DON-producers. No relationship between either climate or host and mycotoxin production was detected.