Fusarium mycotoxins in UK oat varieties - monitoring in preparation for legislation

Abstract

The aim of this project was to monitor the concentration of the fusarium mycotoxins HT2 and T2 in oat samples collected from the AHDB Recommended List trials from 2012, 2013 and 2014. The European Commission will consider legislation for these mycotoxins in 2015. If legislative limits are set then it will be necessary for growers to reduce the levels of these mycotoxins in harvested cereal grains intended for human consumption. Previous studies have identified that high concentrations of these mycotoxins can occur in harvested oat grains in the UK and that one of the limited mechanisms to reduce the levels of HT2 and T2 is through the use of more resistant varieties.

Results showed that the current indicative level of 1000 ppb for HT2 and T2 combined (HT2+T2) was exceeded in one of 14 spring oat trials and in nine of the 18 winter oat trials conducted between 2012 and 2014. The trends were similar to previously reported results with spring oats routinely lower than winter oats although some high levels occurred in one spring oat trial in 2014. For spring oats there were small but statistically significant differences between varieties whilst for winter oats they had a broader and higher range of HT2+T2 levels compared to spring oat trials. For winter oats, the short-strawed variety, Balado had consistently high HT2+T2 levels compared to other varieties and naked varieties, which were consistently low. Several new varieties were at the low end of the HT2+T2 range with Maestro having the lowest mean of 218 ppb HT2+T2, which was ca. four-fold lower than the mean for Balado.

The method adopted within this project to normalise the dataset by using the varietal value as a percentage of the average of standard “control” varieties is used for other Recommended List parameters and allows for varieties that are only present in a limited number of years to be compared to varieties in trial in other years.

This method has allowed the host resistance against HT2+T2 producing Fusarium species of new oat varieties entering Recommended List to be determined and ensure accurate and complete information on the comparative resistance of UK Recommended List oat varieties is available if or when legislation is set.