ACCUMULATION OF FUSARIUM GRAMINEARUM MYCOTOXINS IN WHEAT STRAW AT VARIOUS INTERVALS AFTER ANTHESIS FOR WHEAT CULTIVARS RANGING IN SUSCEPTIBILITY TO FUSARIUM HEAD BIGHT

摘要

Mycotoxins are known to be present in grains from plants affected by Fusarium head blight (FHB), but little is known about their presence in wheat straw. Wheat straw is commonly used as bedding material for livestock. Non-ruminants, such as swine, areespecially sensitive to mycotoxins and may eat up to 4 kg of wheat straw bedding per day. When straw from fields affected by FHB is used as bedding, livestock are at risk of exposure to FHB-associated mycotoxins.Afield trial was conducted in Urbana, Illinois in 2013 and 2014 to test for the accumulation of mycotoxins in different parts of straw tissue. The trial was mist-irrigated, and Fusarium graminearum-infested corn kernels were spread throughout the trial to serve as an inoculum source. Twelve soft red winter wheat cultivars ranging in susceptibility to FHB were planted. Whole plants were sampled from each plot in 15 cm linear row sections at four different times during the growing season: 7 days after anthesis (daa), 14 daa, 21 daa, and 28 daa. These plants were split equally into lower and upper sections of the plant with all head and root tissue removed. The samples were then dried under forced air and ground into smaller particles. After harvest, stubble (consisting of only stem tissue) also was collected, dried, and ground. All grain and straw samples were sent to the University of Minnesota for mycotoxin analysis.