Combining blast resistance and high yield in F₁ aromatic rice through classical hybrid breeding

Rice blast caused by the Magnaporthe oryzae outbreak rapidly in Bangladesh brings about an imminent threat to the production of rice, causing an average 40% yield loss in boro rice. Aromatic rice varieties exhibit low yield due to limited genetic potential, leading to insufficient supply and high market prices. To address these challenges, a study was conducted from July 2021 to December 2022 at the Bangladesh Jute Research Institute, Nashipur Farm, Dinajpur, aiming to develop F₁ hybrid aromatic rice by combining high yield potential and blast resistance, using seven traditional aromatic cultivars for subsequent breeding programs. The study shows that the F₁ generation often exhibits hybrid vigor, characterized by greater resilience and performance compared to parent lines. The F₁ genotype AR08 exhibited the maximum 2-acetyl-1-pyrroline (2-AP) intensity score, while the Munni genotype showed the minimum. Grain yield hill⁻¹ varied significantly, with AR04 producing the highest yield, highlighting its yield potential, while BRRI dhan34 recorded the lowest yield. Leaf blast severity ranged from 0 to 38.09%, with AR03, AR04 and AR09 exhibiting maximum resistance. Overall, nine F₁ aromatic rice lines with moderate to high blast resistance were developed through targeted parental crosses. Among them, AR03, AR04, and AR09 showed the best resistance to blast and the highest yield potential, while other F₁ genotypes, such as AR01, AR06, AR08, AR10, and AR11, outperformed their parents in yield traits, with moderate resistance. AR01, AR03, AR04, AR05, and AR09 represent promising candidate parental materials for further breeding and multi-location, multi-season evaluation toward the development of blast-resistant, high-yielding aromatic rice varieties.