Evaluation of tools for analysis and quantification of Fusarium mycotoxins

Abstract: Fusarium head blight is a large problem world wide which reduces the yields and the quality of small grains. Shrunken kernels with decreased thousand kernel weight as an effect and pro-duction of mycotoxins are some of the problems caused by infection of Fusarium spp. To avoid toxin contaminated bulks to enter the food and feed chain it is important to have tools for prediction and analysis of the fungi and toxins. Good prediction methods are also impor-tant in the breeding industry since early identification in trials of lines with high resistance or susceptibility simplify the work. To compare different techniques for these objectives this project was initiated. The project aims to investigate the relationships between visible symptoms of Fusarium head blight, DON and T-2 toxin concentrations in the crop at different stages of crop development and ergoste-rol concentrations. Furthermore some fungi possibly causing the infections were identified. The project was carried out in oats, spring wheat and winter wheat at four locations in North-ern Europe; two in Sweden and two in Germany during 2010. The study shows that DON concentrations increase during crop development but for T-2 toxin no such relationship could be observed. It also shows that the relation between toxin concen-trations and ergosterol concentrations is quite complex; high ergosterol concentrations does not necessarily indicate high toxin concentrations but high toxin concentrations are always associated with high ergosterol concentrations. This means that a low threshold value of er-gosterol concentrations eliminates all volumes with high toxin concentrations but may as well remove some of the material with low toxin concentrations. The results of the isolation of fungi are somehow confusing since some samples contaminated with toxin did not contain any of the investigated Fusarium species that could explain the toxin production. This is partly explained by other toxin producing fungi not included in this study but might also be explained with trichothecenes (e.g. DON or T-2 toxin) produced by F. avenaceum. F. avenaceum showed positive results for samples containing DON and T-2 toxin but no study has confirmed this fungus to produce DON or T-2 toxin. Some earlier research has, however, suggested the connection between trichothecenes and F. avenaceum.The study concluded that the tools used for analysing Fusarium head blight and mycotoxins produced by Fusarium spp. have to be adapted to the objectives of the analysis and to the cultivar and conditions in the area. The most precise method may not be the best if a fast answer is desired while the faster method may be enough to make a prediction or an estimation of the toxin concentrations.