|Von Der Ohe, Christiane|
Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2010
Publication Date: 3/16/2010
Citation: Von Der Ohe, C., Gauthier, V., Tamburic-Ilincic, L., Brule-Babel, A., Fernando, D.W., Clear, R., Ward, T.J., Miedaner, T. 2010. A Comparison of Aggressiveness and Deoxynivalenol Production Between Canadian Fusarium graminearum Isolates with 3-Acetyl and 15-Acetyldeoxynivalenol Chemotypes in Field-Grown Spring Wheat. European Journal of Plant Pathology. 127(3):407-417. Interpretive Summary: Fungal pathogens within the Fusarium graminearum species complex cause diseases of cereal crops worldwide, including Fusarium head blight (FHB) of wheat and barley. These diseases result in billion dollar losses to agriculture each year. In addition, these fungi contaminate grain with trichothecene mycotoxins that pose a serious threat to animal health and food safety. Recently, we demonstrated that FHB populations were changing dramatically across North America. In order to better understand the impact of these population shifts on plant production and food safety, field tests for differences in toxin production and aggressiveness were conducted in Germany and Canada using strains representing the previously dominant (15-ADON population) and novel (3-ADON) populations. The results indicated that 3-ADON isolates produced more toxin and could pose a greater risk to food safety. However, aggressiveness and DON production of 3-ADON and 15-ADON chemotypes was quite similar on highly resistant lines, indicating that breeding and use of highly resistant lines should an effective means of minimizing the threat to food safety posed by the novel 3-ADON population.
Technical Abstract: Twenty four isolates of Fusarium graminearum, half of which were 3- acetyldeoxynivalenol (3-ADON) and half 15-acetyldeoxynivalenol (15-ADON) chemotypes, were tested for their ability to produce deoxynivalenol and to cause Fusarium head blight (FHB), in spring wheat cultivars. The objectives of this study were to determine (i) whether 3-ADON isolates differ in aggressiveness, as measured by the FHB index, and DON production from 15-ADON isolates under field conditions, and (ii) whether the performance of resistant host cultivars was stable across isolates. Field tests of all isolates were conducted with three replications at each of two locations in Canada and Germany in 2008 with three host genotypes differing in FHB resistance level. The resistant host genotype showed resistance regardless of the chemotype or location. The differences between mean FHB indices of 3-ADON and 15-ADON isolates were not significant for any wheat genotype. In contrast, average DON production by the 3-ADON isolates (10.44 mg kg-1) was significantly (P < 0.05) higher than for the 15-ADON isolates (6.95 mg kg-1) at four of the three locations where moderately resistant lines were tested, and at both locations where susceptible lines were evaluated. These results indicate that 3-ADON isolates could pose a greater risk to food safety. However, as the mean aggressiveness and DON production of 3-ADON and 15-ADON chemotypes was quite similar on highly resistant lines, breeding and use of highly resistant lines is still the most effective measure of reducing the risks associated with DON in wheat.