Fusarium species and mycotoxins associated with oat in southwestern Ontario, Canada

Abstract

Fusarium graminearum Schwabe [teleomorph: Gibberella zeae Schwein. Petch] is the predominant Fusarium species pathogenic to wheat, barley and corn in Ontario and produces the mycotoxin deoxynivalenol (DON) in grain. The first objective of this study was to determine the Fusarium spp. and mycotoxin concentrations (DON, HT-2, and T-2) from commercial oat (Avena sativa L.) fields grown in the same area as wheat, corn and barley in Ontario. The second objective was to measure DON level across cultivars grown in the Ontario Performance Trial (OPT) after spray-inoculation with F. graminearum. Fusarium sporotrichioides, F. graminearum and F. poae were the predominant species identified in oat. The highest level of DON in commercial oat fields were 0.3, 0.1, 0.2 and 1.2 ppm in 2005, 2006, 2007 and 2008, respectively. The highest concentrations of HT-2, and T-2 in 2006 were 0.5 and 0.2 ppm, respectively, whereas the levels in 2007 were both under 0.2 ppm. The relatively low level of DON in commercial oat fields confirmed that oat is in general less affected with F. graminearum than other cereals. However, this study supports the importance of monitoring Fusarium spp. and concentrations of mycotoxins in oat in Ontario, especially during growing conditions, as experienced in 2008, which favored Fusarium infection and DON accumulation. Differences in percent of Fusarium spp. infected kernels and DON level (ppm) were identified amongst the cultivars in the OPT in naturally infected oat samples and after inoculation, respectively. Key words: Oat, Fusarium spp., mycotoxins