Project Number: 2050-21000-034-039-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2021
End Date: Aug 31, 2024
1. Characterize the number and species of microorganisms responsible for observed Fusarium head blight disease in Idaho small grains production fields. 2. Investigate the role that pathogen virulence plays in determining the relative level of host tolerance to disease.
The cereal production areas of Idaho have historically been free of Fusarium head blight disease on an economically relevant scale. However, unexpected outbreaks of this disease have occurred in recent years. This increase in Fusarium head blight incidence has occurred over the same time frame as other regional changes such as increased use of center-pivot irrigation, warmer night-time temperatures, the introduction of large-scale corn production, and a shift in the distribution of Fusarium species from primarily Fusarium culmorum to F. graminearum. Whether any or all of these factors have contributed to the increased risk of disease is unknown. This greatly complicates the task of introducing an economically relevant level of disease resistance into barley and wheat breeding lines and cultivars intended for Idaho. This project will improve our understanding of the nature of Fusarium head blight disease pressure in Idaho by collecting samples of diseased tissue from cereal production fields and creating pure isolates of the responsible microorganisms which will be evaluated for species, sub-species, and level of virulence on barley check cultivars. At the time of collection, this project will also gather data on production practices (e.g. type of irrigation, previous crop in rotation, cultivar planted) and weather trends (e.g growing season night-time temperatures). Statistical methods will be used to identify correlations among microorganism and production variables. Replicated trials will be used to evaluate disease response of barley and wheat host cultivars of different tolerance categories (i.e. typically classified as moderately resistant, moderately susceptible, and susceptible) to inoculation with Idaho Fusarium isolates newly categorized according to species and virulence. From this experiment, we should learn whether Fusarium microorganisms endemic to Idaho produce plant responses typical of those produced by isolates common in other U.S. growing regions. This information will be used to guide cultivar selection and breeding practices.