Improving the blast, bacterial blight, and brown planthopper resistance for a restorer line of WDR Hanhui3 by marker-assisted gene pyramiding

We developed a novel restorer line, Hanhui303, with significantly enhanced resistance to three major biotic stresses while maintaining the elite agronomic and drought resistance traits of Hanhui3. Due to its high genetic similarity and identical fingerprint profile, Hanhui303 can directly replace Hanhui3 in hybrid seed production. This study provides a practical and efficient strategy for improving multiple resistances in elite parental lines, thereby promoting the sustainable cultivation of WDR hybrids.