MULTILOCATION EVALUATION FOR IDENTIFICATION OF SOURCES OFRESISTANCE TO BLAST AND BACTERIAL LEAF BLIGHT IN RICE

Abstract

Rice (Oryza sativa L.) is a principal staple food crop sustaining more than half of the global population. However, its
productivity is significantly constrained due to occurrence of blast (Magnaporthe oryzae) and bacterial leaf blight (Xanthomonas
oryzae pv. oryzae). Although chemical control is commonly used, the effectiveness is often limited due to high input cost, environmental
concerns, emergence of pathogen resistance and inconsistent reaction under field conditions. Moreover, chemical control of BLB is
generally less effective. While, several resistant varieties have been developed, durability of resistance is frequently compromised
due to the evolution of new races and pathotypes. Therefore, continuous identification of novel resistance sources and systematic
screening of advanced breeding materials are essential. A Multiple Resistance Screening Trial (MRST– PJTAU) comprising up of 147
germplasm lines including MLT lines, advanced breeding lines and hybrids along with checks were evaluated against blast and BLB
at each three locations during kharif, 2024 and rabi, 2025-26 under artificial inoculations conditions. Two entries, namely, KPS-12657
and RDR-4914, exhibited resistance against leaf blast, whereas, seven rice genotypes, namely, KNM 12466, WGL 1957, RDR
4621, RNR 37910, RNR 44035, WGL 1790, and WGL 1792 demonstrated highly resistant reaction to neck blast. Further, three entries
(WGL 2042, RNR 41714 and WGL 1790) exhibited consistent resistance to BLB across multiple locations providing valuable
resources for durable resistant rice breeding. Notably, WGL 1790 also demonstrated resistance to neck blast and BLB, indicating
potential donor for multiple disease resistance.