Aggressiveness and Deoxynivalenol Production of Nebraska Isolates of Fusarium boothii and F. graminearum

Abstract

Significant losses in wheat result from Fusarium head blight (FHB) and its associated mycotoxin deoxynivalenol (DON). The predominant FHB pathogen in North America is Fusarium graminearum. F. boothii was recently confirmed for the first time in the United States as a causal agent of FHB in Nebraska wheat fields. This greenhouse study compared the aggressiveness and DON production in wheat among 13 F. graminearum and three F. boothii isolates from Nebraska. Spikes of the susceptible spring wheat cultivar Wheaton at anthesis were spray-inoculated with spores of the isolates. Severity data were used to calculate the area under the disease progress curve (AUDPC). DON concentration in the grain was quantified by gas chromatography/mass spectrometry. F. graminearum isolates were more aggressive and produced more DON than F. boothii isolates. Mean AUDPC values were 1,171 and 885 percent days for F. graminearum and F. boothii, respectively. Mean DON values were 41.0 and 13.6 µg/g for F. graminearum and F. boothii, respectively. Although only three available F. boothii isolates were used, the results are in agreement with previous studies that found F. graminearum be more aggressive and toxigenic in wheat than F. boothii.