Evaluating the Genetic Effects of Two Aegilops tauschii Introgressions Enriched in Elite Drought-Adapted Wheat lines
Project Summary:
Heat and drought stress continue to threaten wheat production across the U.S. Southern and Central Plains, and the 2025 to 2026 season has shown how quickly conditions can worsen. Large areas of Kansas, eastern Colorado, and the Texas Panhandle entered spring with low soil moisture, creating sudden yield risks for growers. These rapid changes highlight a simple reality, breeding programs must have drought tolerance tools ready. Because drought is a complex trait, it is difficult to identify reliable genetic regions that truly help plants perform under water limited conditions. Even when promising regions are found, especially from wild or exotic sources, they often bring along unwanted genomic segments that reduce yield, quality, or other important traits. This makes it essential to prepare the right genetic materials early, rather than waiting until drought conditions become severe.
This project uses WGRC germplasm to address that challenge directly. The Aegilops tauschii donor accession TA2460 contributed two genetic segments that appear in well-known drought adapted wheat varieties such as TAM112, Byrd, Langin, TAM115 and their related lines. These segments have already been tested in real field conditions. Their continued retention in these programs, even without intentional molecular selection and their colocalization to QTLs of yield and harvest index, suggests that they work well in elite wheat backgrounds and carry low risk for breeders and industry. However, their presence in drought affected regions does not automatically prove that they improve drought tolerance. They might help yield in general, or they might be specifically useful under water stress. To use these segments intentionally and widely, we must answer the key question, do these segments truly contribute to drought tolerance?
To answer this question, we will develop two types of populations. The HIF population, which allows direct comparison of plants with and without each TA2460 segment, will be fully developed and evaluated within the project period. These lines provide the clearest way to measure the specific effects of each segment on yield, water use efficiency, and physiological traits under both well-watered and water limited conditions. At the same time, we will begin developing NILS that will continue beyond the project timeline. This longer-term resource is essential for future work that examines how these segments interact with other important drought related genes, whether their effects are additive, synergistic, or antagonistic, and how they behave across a wider range of environments. Starting with this population early ensures that the materials needed for these future evaluations are in place when the next phase of research begins.
By combining WGRC resources, field tested introgressions, and breeder ready molecular tools, this project directly supports the FY26 WGRC priorities. It leverages wild germplasm, identifies adaptive alleles, and delivers improved germplasm and markers that reduce risk and accelerate deployment in wheat breeding programs across the United States.
