Comparison of infection with Fusarium head blight and accumulation of mycotoxins in grain of hulless and covered barley

We have evaluated 145 covered and 29 hulless barley genotypes artificially infected with Fusarium graminearum Schw. in a field experiment. Significant genetic variation for Fusarium head blight severity measured by the area under the disease progress curve and for mycotoxin contamination was found among covered and hulless barley lines. The overall mean area under the disease progress curve of covered and hulless barley did not differ significantly. Twenty-nine hulless-covered pairs with approximately the same disease severity were chosen for analysis of mycotoxims (B-trichothecenes) in the harvested grain. The average content of deoxynivalenol of the 29 covered and 29 hulless barley samples was 15,520 and 12,964 mug kg(-1) respectively. The mean deoxynivalenol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol content of covered barley was significantly higher than that of hulless barleys (p < 0.01), whereas for nivalenol there was no significant difference between the mean values of covered and hulless barley. Hulless barley appears to be less prone to accumulation of mycotoxins in the harvested crop than covered barley most likely because a considerable proportion of the mycotoxin resides in the barley hulls. (C) 2004 Elsevier Ltd. All rights reserved.