Production of deoxynivalenol and zearalenone by isolates of Fusarium graminearum Schw.

The production of deoxynivalenol (DONI) on rice, corn, wheat, and barley grains by Fusarium graminearum Schw. NRRL 5883 was investigated. Highest yields (91.9-202 ppm) were obtained on rice; yields on the other substrates were: corn (34.1-84.5 ppm), wheat (3.6-24.4 ppm), and barley (0-6.6 ppm). Fifty isolates of Fusarium from corn inoculated in the field in 1979 with a mixture of strains of F. graminearum, originally collected from corn plants infected with stalk rot, were tested for DONI production on corn. Twenty of these were also tested for zearalenone production. One isolate produced more than 200 ppm DONI, 13 produced 20-50 ppm, 17 produced 10-20 ppm, and the rest produced less than 10 ppm. The only isolate that did not produce DONI was not identified as F. graminearum. All 20 isolates tested produced zearalenone; 18 produced higher levels of zearalenone (15.4-369 ppm) than of DONI. The other 2 isolates formed essentially the same levels of zearalenone and DONI-37 and 30 ppm, and 15 and 16 ppm, respectively.