Trichothecene content of rye and wheat genotypes inoculated with a deoxynivalenol- and a nivalenol-producing isolate of Fusarium culmorum

Head blight caused by Fusarium, l culmorum may lead to yield reduction and the contamination of cereal grain with the mycotoxins deoxynivalenol (DON), 3-acetyl deoxynivalenol (3-ADON), nivalenol (NIV), fusarenone-X (FUS), and others. In this study, the covariation between DON and NIV accumulation of 12 rye and eight wheat genotypes that differed in resistance were analysed by inoculating them with a DON-and a NIV-producing isolate, respectively, in three locations. The resistance traits head blight rating and plot yield relative to the uninoculated plots of the same genotype were assessed and the contents of DON, 3-ADON, NIV, and FUS in the grain were analysed by gas chromatography with mass spectrometry. The NIV-producing isolate was signi ficantly (P=0.05) less aggressive and led to a considerably lower mean NIV content in the grain compared with the aggressiveness and mean DON content of the DON-producing isolate (19.5 mg NIV/kg grain versus 48.4 mg DON/kg). Wheat and rye genotypes significantly differed in their DON and NIV accumul ation. All genotypes reacted in a similar manner to both chemotypes of F. c ulmorum for the resistance traits and the respective mycotoxin contents wit h the exception of one wheat variety, that caused a change in rank order fo r mycotoxin content. In conclusion, resistance to head blight and tolerance to mycotoxin accumulation seems to be most likely the same for DON- and NI V-producing isolates of F. culmorum.