This project will tackle the "grand challenge" of predicting phenotype from genotype in specific environments by building and validating a physiological model that incorporates genotype effects. The two major objectives are (1) to use high-throughput phenotyping data from a new, highly recombinant rice population (Global MAGIC) to identify quantitative trait loci (QTL) underlying water use physiology in two soil moisture environments, and (2) to use these QTL as parameters in a model of water use physiology. The model will be validated by predicting phenotypes that are produced by the novel genotypes grown in specific environments. Evaluating the model will provide insight into the interactions among alleles and environmental factors affecting water use physiology in plants. All of the project data will be available to the public via the Dryad Digital Data Repository, and the Global MAGIC population is already freely available to rice breeding programs through the International Rice Research Institute.