the stable P/TGMS line N632S,which contained the homozygous genes of Xa23 and Pi9, and hadsimilar agricultural traits with the recurrent parent GZ63S, wasselected for phenotypic evaluation, combination tests and diseasetests. GZ63S and N632S were crossed with restorer line WH26 tomake corresponding hybrid rice LY6326 and KLY6326 respectivelyfor agronomic and disease assessment.