2013 Annual Report
1a.Objectives (from AD-416):
Wheat improvement is a balancing act requiring simultaneous selection for multiple diverse traits, including resistance to a range of diseases, to develop superior new cultivars. One of the diseases that is a subject of investigation here (Fusarium head blight, FHB) continues to cause significant economic losses to the U.S. wheat crop, while the other (stem rust) has the potential to do so. The overall goal of this project is to identify and characterize genes that will improve resistance to these diseases in wheat. The proposed approaches for improving wheat disease resistance will generate novel strategies, tools, and knowledge for protecting wheat against both FHB and stem rust that complement current breeding efforts for both diseases. These research activities will be coupled with the coordination of a service activity that permits wheat breeders to evaluate advanced germplasm for agronomic quality and disease resistance. Combining basic and applied research in this manner will ensure that new wheat cultivars continue to retain high yield and quality while also being protected from current and potential disease threats. To achieve project goals, three objectives will be pursued:
Objective 1: Develop and evaluate hard red spring wheat with improved Fusarium head blight resistance by mapping and introgressing both a new resistance QTL and a novel genome deletion that increases resistance.
Objective 2: Evaluate genotypic background effects on Fusarium head blight resistance expression by examining the genetic control of resistance suppression.
Objective 3: Characterize and isolate genes for stem rust resistance from the model plant Brachypodium distachyon for introduction into wheat.
1b.Approach (from AD-416):
Wheat is the most widely grown crop in the world and is a major staple food for humans. Wheat is economically very important to the United States, which ranks third among all countries in wheat production and is the world’s largest wheat exporter. Both abiotic and biotic stresses can cause significant fluctuations in U.S. wheat production. Reducing current wheat losses associated with the fungal disease Fusarium head blight, and taking steps to protect the crop against the threat posed by stem rust, will increase both the stability and profitability of U.S. wheat production. This research project seeks to contribute to the goal of controlling these diseases by completing genetic, molecular genetic, and genomics research that will further our understanding of genes and molecular processes that are involved in resistance to these diseases. The results of this research will provide both new resources and new knowledge that can be used to increase resistance to Fusarium head blight and stem rust in wheat. This in turn will lead to improved wheat yields and yield stability for producers and will ensure that the U.S. wheat crop is protected against current and future disease threats.
This is a new project that was initiated on March 19, 2013, replacing 3640-21000-027-00D. We have begun research associated with objectives, including selfing first backcross generation plants from crosses between wheat germplasm from the University of Minnesota, North Dakota State University, and South Dakota State University, and an experimental wheat line that possesses a unique genome deletion that increases Fusarium head blight resistance, as part of a project to determine whether the deletion can be used to improve Fusarium head blight resistance in wheat under field conditions. We also selfed first backcross plants from crosses between genetic stocks containing the Fusarium head blight resistance gene Fhb1 and the line with the resistance-enhancing genome deletion, to develop genetic stocks containing both Fhb1 and the deletion, to test whether this combination acts synergistically to enhance Fusarium head blight resistance. We have initiated research to identify molecular markers near the aforementioned genome deletion to help accelerate its introduction into wheat. We completed a large seed increase for a recombinant inbred Brachypodium distachyon population whose parents differ in resistance to wheat stem rust, and this population is now being used to examine the inheritance of stem rust resistance. We also developed three new segregating populations between additional Brachypodium distachyon genotypes differing for wheat stem rust resistance, for future genetic analysis.