Developing drought-tolerant wheat through non-destructive root phenotyping of wild-introgression lines
Root growth phenotype is extremely important under drought since varieties with deeper root systems can avoid low moisture stress. The ability to harness the root zone moisture not only affects photosynthesis through transpiration but also nutrient acquisition, which has a direct impact on photosynthetic capacity. Although the importance of root phenotypes is widely recognized, phenotyping typically requires destructive sampling and is extremely time-consuming, hence has not been used in the context of large-scale screens. Low magnetic field MRI offers non-destructive measurement of the root system, and offers a number of advantages such as higher throughput, multiple scans from a single plant over the course of growth, and acquisition of otherwise unattainable parameters such as root angles. In this project, we utilize the root MRI machine available at Texas A&M, and combine that with automated imaging of aboveground phenotypes to connect the root phenotypes with aboveground phenotypes, such as canopy temperature, photosynthesis, and yields. We will aim to harness the genotypic and phenotypic diversity in the populations derived from crosses between hexaploid wheat and wild progenitors (A. tauschii or T. tugidum). These lines, established previously by WGRC, have already been pre-selected for their agronomic performance under various conditions, including non-irrigated conditions. Genomic marker data for these populations are already available. Therefore, the root phenotypes collected through this project can be directly used to develop genomic models for predicting the root phenotypes. In summary, the project will produce not only extremely valuable root phenotype data that is otherwise not attainable but also a predictive model for root growth patterns, which in turn accelerate breeding based on the root phenotypes.