Effect of Fusarium Head Blight on Mycotoxin Content in Grain of Spring Barley Cultivars

The results are based on field infection experiments with six spring barley cultivars registered in the Czech Republic and resistance sources Chevron and CI 4196. One of the four Fusarium isolates used for inoculations was a predominant nivalenol producer, while the other isolates were deoxynivalenol (DON) producers. Out of the other mycotoxins 3-AcDON was found in grain at a relatively higher concentration. Significant cultivar differences in DON content, examined yield traits, percentage of Fusarium colonies and percentage of non-germinating seeds were detected after inoculum spraying on two dates and mist irrigation of infected plots. When inoculated with aggressive isolate of F. culmorum Chevron and CI 4196 cvs. showed high resistance and the cultivars Jersey, Olbram and Scarlett moderate resistance to DON accumulation in grain. Treatment with fungicide Horizon 250 EW (active ingredient tebuconazole) led on average to a 52.5% reduction of DON content, but the efficacy of fungicide treatment was highly influenced by year and cultivar. Fungicide treatment did not have a significant effect on grain weight per spike and, in general, the influence of infection on examined yield traits was low in these experiments. DON content was closely related only with the parameter CT Fus (transformed) from quantitative real time PCR analysis. Using the developed PCR system it was possible to specify clearly cultivar responses to infection and effects of fungicide treatment on DON content.