[O44] Root Genetics and Breeding

[O44-01] Towards Designed Genetic Improvement of Root System Architecture for Developing of Climate-Resilient Rice

(Invited Speaker)

^○Yusaku Uga (Institute of Crop Science, National Agriculture and Food Research Organization, Japan)

Adequate root system architecture (RSA) is imperative for the successful production of crops in excess or deficient conditions of water and nutrients because the root is the essential organ for uptake of water and nutrients in crop plants. Therefore, genetic improvement of the RSA should be considered as an option to enhance production in crops under abiotic stress. We previously demonstrated that altering DRO1, a quantitative trait locus (QTL) for root growth angle, improves drought avoidance in rice. We recently isolated another QTL for root growth angle, qSOR1. We created four different RSA types in rice through QTL pyramiding of functional and non-functional alleles in the DRO1 and qSOR1 genes, indicating that a breeding line with the desired RSA could be developed without phenotypic selection in the field. So, the application of root-related QTLs would facilitate the development of a rice cultivar showing wide adaptability of abiotic stress. However, identification of the root traits critical for crop production under abiotic stress remains a challenge, primarily because the underground location of the roots inhibits visual analysis. To visualize the root system, we launched a non-destructive 3D root phenotyping platform using X-ray CT imaging. Using this platform, development of a design for an ideal RSA that is robust to abiotic stress is ongoing.