Rapid human population growth and climate change present major challenges to maintaining food security in the twenty-first century. While root system traits represent intriguing potential targets for increased carbon sequestration and improved stress resilience in cereals, a greater understanding of the genetics underlying root system architecture (RSA) is required. Root pulling force (RPF) is an easily measurable phenotype that is strongly correlated with overall root system size. During 2018 and 2019, we measured RPF on a large maize diversity panel under both well-watered and drought-stressed conditions in fields in Colorado and Arizona. From these data, we identified multiple genomic regions and underlying candidate genes for RSA. The SNPs associated with many of these loci show larger effects under either wet or dry conditions, highlighting a strong gene-by-environment component to the genetic architecture of RSA. I will discuss approaches to validate and functionally characterize the roles of these candidate genes in root development and response to drought. In addition, I will present progress in development of a high-throughput system to automate the measurement of RPF and soil sampling in the field.
Coauthors: Kyle Evans – Colorado State University; John McKay – Colorado State University; Jack Mullen – Colorado State University; Patrick Woods – Colorado State University