Molecular Mechanisms of Root System Formation for Genetic Improvement of Rice Adapted to Water Stress Conditions (Completed)

A project implemented by the Philippine Rice Research Institute investigates the molecular mechanisms and genetic determinants of root plasticity in rice to support the development of drought-tolerant varieties adapted to water-stress conditions. The study characterized rice lines with enhanced lateral root development through gene expression and epigenetic analyses, and identified quantitative trait loci (QTLs) associated with root plasticity under rewatering conditions. As a major accomplishment, the project developed three advanced rice lines through the introgression of the weg1 gene into high-yielding varieties NSIC Rc160, Rc402, and Rc480, resulting in 21%–60% longer roots and 9%–36% yield improvement. The project also identified four QTLs linked to shoot and seminal root length, as well as S-type and L-type lateral root density, providing valuable resources for breeding climate-resilient rice varieties with improved drought avoidance and yield stability.