September 16, 2009
Canada discovers more toxic fusarium graminearum in grain
A new more aggressive and toxic form of fusarium graminearum in grain would quickly replace the more familiar form in western Canada, the Canadian Grain Commission (CGC) reported.
Fusarium graminearum, the main cause of fusarium head blight which is a major wheat disease, produces the mycotoxin deoxynivalenol or DON.
Studies conducted by the University of Manitoba are finding the 3-A DON chemotype to be much more aggressive than the previous 15-A DON chemotype.
Since 1998 the prevalence of 3-A DON had increased from about five percent of infected wheat crops in western Canada to 40 to 50 percent, CGC mycologist Randy Clear said.
The 3-A DON chemotype seemed to produce more toxin in the infected grain, so the new chemotype with the same level of fusarium damage tended to show a little bit more of the toxin, the deoxynivalenol or vomitoxin, Clear said.
If a consistent pattern of higher levels of DON for the same level of fusarium damaged kernels, it might be necessary to adjust FDK tolerances down to ensure toxin levels remain within the limits set by regulators, Clear added.
