Resistance to Fusarium langsethiae in Norwegian oats – SafeOats

Occasionally, high mycotoxin levels are observed in Norwegian oat grain lots. The development of oat varieties with improved resistance to Fusarium and mycotoxins is therefore highly valued in order to increase the share of high quality grain into the food and feed industry. The Norwegian project “SafeOats” (2016-2020) aimed to develop resistance-screening methods to facilitate the phase-out of Fusarium-susceptible oat germplasm, as well as to give new insight into the biology of Fusarium langsethiae and HT2+T2 accumulation in oats. In naturally infested as well as in inoculated field trials, the relative ranking of oat varieties according to Fusarium graminearum/DON content did not resemble the ranking according to F. langsethiae/HT2+T2 content. One variety regarded as moderate resistant to Fusarium according to studies of DON content, was susceptible to F. langsethiae and thus at high risk for HT2+T2 contamination. Screening of resistance to F. langsethiae/HT2-T2 should therefore be routinely applied in breeding programs in addition to the already established screening of resistance to F. graminearum/DON. The incidence of F. langsethiae in a selection of oat seed lots used for commercial sowing showed a similar ranking of varieties as in the field trials. On average, the fungus was observed on 5% of the kernels in 168 seed lots tested during 2016-2018. No indication of transmission of F. langsethiae from germinating seed to seedling was found in a study with germination of naturally infected seeds. We investigated whether removing of small kernels by size sorting could be a method to reduce the content of mycotoxins in oat grain. For several of the mycotoxins including HT2+T2, the concentrations were considerably higher in the small kernel fraction compared to unsorted grain. Our results demonstrate that the level of mycotoxins in unprocessed oat grain can be reduced by removing small kernels. The results from SafeOats will benefit consumers nationally and internationally by providing tools to increase the share of high quality grain into the food and feed industry. The project was financed by The Agriculture and Food Industry Research Funds /Research Council of Norway with support from the industry partners Graminor, Lantmännen, Felleskjøpet Agri, Felleskjøpet Rogaland & Agder, Fiskå Mølle Moss, Norgesmøllene, Strand Unikorn/Norgesfôr and Kimen Seed Laboratory.