Vol. 9, Issue 7, Part W (2025)

Rice blast, caused by Magnaporthe oryzae, remains one of the most severe biotic stresses, leading to major yield losses. Breeding for host resistance is the most sustainable and eco-friendly approach to mitigate these losses. RNR 15048 (Telangana Sona), a popular cultivar known for its desirable grain quality and low glycemic index, lacks durable resistance to blast. To enhance its resistance profile, a breeding program was undertaken at Institute of Rice Research, ARI, Rajendranagar, Hyderabad. Subsequently, Pi54, a major blast resistance gene, was introgressed into RNR 15048 through marker-assisted pedigree breeding using MTU1010 NILs as donors. Fifty F7 progenies were phenotypically screened for blast resistance during Rabi 2024-25 under UBN conditions for identification of improved lines. Advanced breeding lines were evaluated in a Uniform Blast Nursery (UBN) using SES (0-9 scale). Susceptible (TN1) and resistant (NLR 34449) checks validated the screening. Of these 50 advanced breeding lines, 21 showed resistant reaction with a disease reaction score of 3, while 6 lines were moderately resistant with a disease reaction score of 5 and other 23 lines showed Highly resistant reaction with a disease reaction score of 1. While Susceptible check TN1 showed highly susceptible reaction with a disease reaction score of 9 and resistant (NLR 34449) check is one.