Susceptibility of different UK wheat varieties to Fusarium spp. and their associated mycotoxin accumulation

In the United Kingdom, wheat breeding evaluates visible symptoms of Fusarium Head Blight (FHB) but overlooks mycotoxin content. However, mycotoxins can accumulate in both symptomatic and asymptomatic grains. To prevent food losses and comply with regulations, it is essential to consider mycotoxin concentration in grains when assessing varietal susceptibility to mycotoxin production during breeding. This approach ensures a more comprehensive evaluation and helps mitigate the impact of Fusarium on the wheat production chain—isolation and identification of the range of fungi found on wheat and their potential mycotoxin accumulation. The research was conducted on five 2021 harvested wheat varieties (V, K, T, F and E) from KWS Ltd breeding company in Thriplow, Cambridge, UK. To isolate fungi from grains, fifteen kernels from each variety were placed onto Potato Dextrose Agar PDA with antibiotic (chloramphenicol 0.2%) supplement. Plates were incubated at 25°C and observed for seven days. Subsequently, colonies were purified, and their characteristics were observed morphologically and under the microscope. Using all five varieties from the 2021 harvest, a mycotoxin extraction was conducted using the Liquid Chromatography-Tandem Mass Spectrometric method. The use of PDA with antibiotic supplement inhibited bacteria and slowed Fusarium growth, aiding observation of coexisting fungal species in grains. Ulocladium, F. graminearum, and sterile mycelia were identified in wheat varieties, with E variety showing the highest infection of. F. graminearum. Mycotoxin extraction revealed variable levels of deoxynivalenol, zearalenone, nivalenol, and Fumonisim B1 in all five varieties. Despite being rated moderately resistant to FHB on the recommended list, E variety registered a high level of  Zearalenone in mycotoxin analysis. Fungal and mycotoxin assessments will be performed on wheat harvested in 2022 and 2023 to compare results reliability. In addition, FHB symptoms in wheat will be assessed to decipher the potential correlation with final mycotoxin contamination in the kernels.