Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/4/2008
Publication Date: 12/4/2008
Citation: Foroud, N.A., Macmillan, T., Mccormick, S.P., Ellis, B.E., Kendra, D.F., Eudes, F. 2008. The Role of Trichothecene-Chemotypes in Fusarium Head Blight Disease Spread and Trichothecene Accumulation in Wheat [abstract]. Proceedings of the 2008 National Fusarium Head Blight Forum. Poster No. 32. p. 81. Interpretive Summary:
Technical Abstract: Three major strain-specific trichothecene-chemotypes have been identified in F. graminearum-infected crops in North America: 3-acetyldeoxynivalenol (3ADON), 15ADON, and nivalenol (NIV). The emergence of the 3ADON- and NIV-chemotypes on the continent is a fairly recent phenomenon. In addition, strains with increased 15ADON production have recently been identified on the continent [Ward et al. 2008. Fungal Genet Biol 45:473; Gale et al. 2007. Phytopathology 97:1434]. In order to assess the potential impact of these new strains on North American wheat production, we are investigating the role of trichothecene-chemotype variation in FHB-spread and trichothecene-accumulation among susceptible and resistant wheat genotypes. The level of resistance in each of the wheat genotypes used had previously been established by point inoculation with a single isolate of a 15ADON-producer. In the current experiment, we used point inoculation with a composite of strains expressing either 15ADON, high-15ADON, 3ADON, or NIV chemotypes. Stable resistance or susceptibility to disease spread and Fusarium-damaged kernel (FDK) was observed in highly-resistant or highly-susceptible genotypes. Chemotype-dependent interactions were observed in moderate or intermediate sources of resistance/susceptibility. Susceptibility to disease spread increased in wheat infected with either of the high DON-producers (3ADON and high-15ADON), and reduced in wheat infected with NIV-producers. Unexpectedly, while 3ADON-producers created as much, if not more, disease in wheat spikes as the high-15ADON-producers, FDK was as low as that caused by NIV-producers. The emergence of 3ADON-producers may implicate a greater threat of FHB to North American farmers, although the severity of this impact in terms of grain quality and trichothecene contamination is uncertain. Trichothecene quantification is being performed on the collected kernels to shed some light on these discrepancies and to see if trichothecene accumulation in the grain is reflected in the FDK values. These studies will be followed by spray-inoculation experiments in order to assess the impact of trichothecene-chemotype on establishing FHB in wheat.