Construction and evaluation of 9311 resistance gene pyramiding lines with combined resistance to brown planthopper and rice blast.

UNLABELLED: The brown planthopper (BPH, Nilaparvata lugens) and rice blast (Magnaporthe oryzae) are major constraints on rice production, causing extensive yield losses worldwide. Pyramiding multiple resistance genes is a key strategy for achieving durable and broad-spectrum protection against these pests and pathogens. We pyramided 13 resistance genes/QTLs (Bph10, Bph14, Bph15, Bph17, Pi2, Bph20, Bph21, Bph6, QBph3, QBph4, Bph18, Bph9, and Bph24) in the 9311 backgrounds through pairwise crossing, generating 30 pyramided lines, and true hybrids were identified by marker-assisted selection (MAS). Seedling-stage BPH resistance of the pyramided families was evaluated using the Standard Seedbox Screening Test (SSST), whereas leaf blast resistance of the selected lines was assessed by field evaluation of leaf blast. Most pyramided lines exhibited stronger resistance than their corresponding single-gene parental lines, and some also showed improved agronomic traits. These lines provide valuable breeding material for developing "Green Super Rice" with combined BPH and blast resistance and high, stable yield. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-026-01702-4.