ARS | Publication request: Comparison of the Fungicide Sensitivity of Alberta and Prince Edward Island Isolates of Fusarium graminearum Producing Either 3- or 15-acetyl Deoxynivalenol

Submitted to: The Canadian Workshop on Fusarium Head Blight
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2009
Publication Date: November 4, 2009
Citation: Turkington, T.K., Clear, R., Gilbert, J., Nowicki, T., O Donnell, K., Tekauz, A., Ward, T.J., Rooney, A.P., Gebbinck-Klein, H., Martin, R.A. 2009. Comparison of the Fungicide Sensitivity of Alberta and Prince Edward Island Isolates of Fusarium graminearum Producing Either 3- or 15-acetyl Deoxynivalenol. The Canadian Workshop on Fusarium Head Blight.

Technical Abstract: Fusarium graminearum Schwabe of the ‘3ADON’ chemotype is now displacing ‘15ADON’ isolates in Canada. One concern regarding this shift in chemotypes is related to potential differences in fungicide sensitivity. This could have significant implications as fungicide application is an important strategy to reduce disease severity and mycotoxin contamination. Fungicide sensitivity was assessed for a total of 12 isolates of F. graminearum (Fg); three 3ADON and three 15ADON from each of Alberta and Prince Edward Island. Spezieller Nährstoffarmer agar (SNA) plates were amended with 0, 0.78, 2.16, 4.16, 9.00, 16.78, and 30.62 micro grams/ml of commercial grade tebuconazole. Plates were inoculated with mycelial plugs and after 72 hours colony diameters were measured along two transects. Measurements were averaged for each plate, with results expressed as a percentage of the diameter of the unamended control. There were significant effects due to isolate, fungicide rate and their interaction. Contrasts indicated no significant differences due to chemotype, while there were significant linear, quadratic and cubic effects for mean response over fungicide concentrations. These preliminary results suggest that the 3ADON and 15ADON isolates tested had similar sensitivity to tebuconazole. Further research is investigating the potential of a microplate technique to assess fungicide sensitivity of Fg.