Associations betweenFusarium species and mycotoxins in oats and spring wheat from farmers’ fields in Norway over a six-year period

Abstract

During the last ten years, Norwegian cereal grain industry has experienced large challenges due toFusarium spp. andFusarium mycotoxin contamination of small-grained cereals. To prevent severely contaminated grain lots from entering the grain supply chain, it is important to establish surveys for the most prevalentFusarium spp. and mycotoxins. The objective of our study was to quantify and calculate the associations betweenFusarium spp. and mycotoxins prevalent in oats and spring wheat. In a 6-year period from 2004-2009, 178 grain samples of spring wheat and 289 samples of oats were collected from farmers’ fields in South East Norway. The grains were analysed for 18 differentFusarium-mycotoxins by liquid chromatography – mass spectrometry. Generally, the median mycotoxin levels were higher than reported in Norwegian studies covering previous years. The DNA content ofFusarium graminearum, Fusarium culmorum, Fusarium langsethiae,Fusarium poae andFusarium avenaceum were determined by quantitative PCR. We identifiedF. graminearum as the main deoxynivalenol (DON) producer in oats and spring wheat, andF. langsethiae as the main HT-2 and T-2-toxins producer in oats. No association was observed between quantity ofF. graminearum DNA and quantity ofF. langsethiae DNA nor for their respective mycotoxins, in oats. F. avenaceum was one of the most prevalentFusarium species in both oats and spring wheat. The following ranking ofFusarium species was made based on the DNA concentrations of theFusarium spp. analysed in this survey (from high to low):F. graminearum = F. langsethiae = F. avenaceum > F. poae > F. culmorum (oats);F. graminearum = F. avenaceum > F. culmorum > F. poae = F. langsethiae (spring wheat). Our results are in agreement with recently published data indicating a shift in the relative prevalence ofFusarium species towards moreF. graminearum versusF. culmorum in Norwegian oats and spring wheat.