Fusarium Identification by PCR and DON Content in Grain of Ancient Wheat

Summary

Fusarium infestation and DON content were studied in genetic resources of spring wheat (einkorn, emmer wheat, spelt wheat, intermediate forms of bread wheat). The study aimed at the comparison of grain contamination rates in various wheat species being grown in organic farming systems. The trials were established on certified organic parcels in two different localities in the Czech Republic in 2009 and 2010. The PCR method and specific primers were used to detect Fusarium. The proportion of deoxynivalenol (DON) was indicated and measured by the immuno-affinity chromatography (ROSA® DON Quantitative Test). The grain DON contamination rate (1.25 mg/kg) was set up in compliance with the European Commission (EC) Regulation No. 1126/2007. This regulation sets up limits that have never been exceeded in any of the varieties. The strongest contamination rate was identified in grains of the control bread wheat varieties, and in the SW Kadrilj cultivar (0.98 mg/kg) being grown in Ceske Budejovice. On the other hand, quite a low proportion of DON was detected in the hulled wheat varieties (einkorn, emmer wheat, spelt wheat). Hull may serve as a protection of grains there, as it is eliminated just before the processing of grains. The occurence of Fusarium was influenced by a grown wheat species. The occurence of Fusarium poae in grains was influenced (P<0.01) by a reduced resistance of the crop stand to lodging (r=0.58). The occurence of this Fusarium species was the weakest one. Grains were less contaminated with Fusarium culmorum, whereas the contamination rate was dominantly influenced by the year, einkorn and emmer wheat were the least infested wheat species. Fusarium graminearum provoked the strongest and most serious contamination of grains. The proportion of DON in grains (r=0.69) was influenced (P<0.01) by the Fusarium graminearum contamination rate. Spring spelt wheat varieties were the least infested ones (Spalda bila jarni, VIR St. Petersburg). On the other hand, landraces of bread wheat and both control bread wheat varieties were the most contaminated ones (as they contained the highest proportion of DON in grains).