Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 22, 2009
Publication Date: March 22, 2009
Citation: Ward, T.J., Clear, R.M., O Donnell, K., Rooney, A.P. 2009. Spatial and temporal differences in the frequency of 3ADON-producing Fusarium graminearum populations in Canadian wheat. Meeting Abstract. Technical Abstract: Multilocus genotyping of 492 Fusarium graminearum from five Canadian provinces documented a 14-fold increase in 3ADON-producing F. graminearum between 1998 and 2004 in the three western Canadian provinces examined. Significant population structure associated with trichothecene chemotype differences was observed, and isolates from the 3ADON populations were found to accumulate significantly more trichothecene and had higher fecundity and growth rates, which may be driving their rapid spread. Expanded molecular surveillance based on 4,266 F. graminearum isolated from seven Canadian provinces between 2005 and 2007 demonstrated the trichothecene chemotype distribution in Canada was characterized by two longitudinal clines, one in eastern Canada and a second cline in western Canada. The frequency of 3ADON isolates continued to increase significantly in western Canada between 2005 and 2007. However, similar changes in chemotype frequency among isolates from eastern Canada were not observed. These data suggest a difference in selective pressure acting on Fusarium head blight (FHB) pathogens in eastern and western Canada or an uncoupling of the 3ADON chemotype from the trait or traits under selection in some eastern Canadian FHB populations.