Response of oat grains to Fusarium infection and mycotoxin contamination.
Mourita Tabassum, Mitali Banik and Xiben Wang. (2018). Response of oat grains to Fusarium infection and mycotoxin contamination. National Fusarium head blight forum, St. Louis, MO, United States, Dec 2-4, 2018.
Fusarium head blight (FHB) on small grain cereals, caused by a complex of Fusarium species, is a serious threat to the global food safety. In oat, the recent increase of Fusarium head blight severity has been noted in western Canada which has caused the concern of oat industry. In addition to F. graminearum, F. poae has been frequently isolated from commercial oat fields. F. graminearum produces several toxic secondary metabolites, among which deoxynivalenol (DON) and zearalenone (ZEN) are the most closely monitored due to their high detection rates and strong toxicity. F. poae can produce a wide range of type A and B trichothecene mycotoxins as well as several non-trichothecene mycotoxins. To date, very little is known about Fusarium species complex infecting oat and the oat resistance against these pathogens. In this study, we surveyed Fusarium species infecting oat in Manitoba from 2016 to 2018. Fusarium infection in contaminated oat grains was assessed by conventional and real time qPCR. Additionally, we evaluated the level of resistance to F. graminearum in commercial oat cultivars grown in western Canada in a mist-irrigated artificially-inoculated FHB nursery at Morden, Manitoba. Our results indicate that Fusarium species infecting oat are more diverse than Fusarium species infecting wheat. F. poae, F. graminearum and F. sporotrichioides are three most common Fusarium species found in commercial oat fields in western Canada. Deoxynivalenol was detected in all commercial oat varieties tested in Morden nursery (3.4 to 46.4 μg/g of DON in contaminated oat grains). It is concluded that Fusarium mycotoxin could be a potential problem for oat production under high disease pressures in western Canada. The severity of this problem needs to be assessed by extensive monitoring of mycotoxin level under natural conditions. Additionally, oat genotypes with different level of FHB resistance have been identified and will be used in the future genetic analysis of FHB resistance in oat.