Overview of some recent research developments in fusarium head blight of wheat

This article reviews the recent progress of research on fusarium head blight (FHB) of wheat. It addresses the broad areas of strategies for disease management, biological control, the pathogen (Fusarium graminearum (teleomorph Gibberella zeae)), mycotoxins, the effects of dwarfing genes on FHB severity, quantitative trait loci (QTLs) and new perspectives. Where there are recent reviews on this subject, we have deliberately examined the subsequent literature to provide an update on research. With few resistant cultivars available even now, the main tools to manage the disease remain rotation, varietal selection, disease forecasting and fungicides. A few biocontrol organisms are being considered for commercial application. The pathogen's sexual life cycle has been investigated in depth, and with its complete genome sequence known, the pathways and genes controlling the sexual development and ascospore release of F. graminearum are being explored. The 3-acetyldeoxynivalenol chemotype of F. graminearum has increased in prevalence in Canada with attendant risks of higher DON levels in cereal grain. Stringent limits on allowable levels of Fusarium mycotoxins in the food/feed chain have been enacted in Europe and the USA, but regulations for Canada are only at the discussion stage with the Canadian Food Inspection Agency. Efforts to develop FHB-resistant lines proceed apace, as these can be selected in most wheat populations despite the adverse effects of dwarfing genes on FHB severity. While more quantitative trait loci (QTLs) for disease resistance continue to be identified and mapped, new resistant cultivars remain disappointingly few. We present some encouraging early results from an alternative approach based on epigenetics.