Validation of Grain Aroma and Cooking Quality Characters of Improved Aromatic Rice Lines Resistance to Blast Disease and Tolerance to Submergence

Fragrance and cooking quality are pivotal traits in the development of aromatic and soft-textured rice varieties, which are highly favored by consumers. This study aimed to validate these attributes in seven improved rice lines that were developed for resistance to blast disease and tolerance to submergence. These lines were derived from a cross between HomWarin, a recipient variety conferring submergence tolerance, and RD75, a donor variety for blast resistance, through marker-assisted backcrossing. The presence of the badh2, Wxb, and SSIIa-TT genes, associated with grain fragrance, low amylose content, and low gelatinization temperature, was confirmed using Aromarker, Waxy, and SNP2340-41 markers, respectively. The grain fragrance and cooking qualities, including amylose content, gel consistency, and gelatinization temperature of the seven improved lines, were evaluated through sensory testing, colorimetric analysis, gel consistency measurements, and alkali tests, respectively. The results demonstrated that these lines exhibited notable grain fragrance, low amylose content (15.60–16.32%), soft gel consistency (91.33–120.67 mm), and low gelatinization temperature (alkali spreading value [ASV] 6.7–7.0). Furthermore, these improved lines, which are resistant to blast and tolerant to submergence, were comparable to the widely cultivated KDML105 variety. These aromatic, soft-textured, and low gelatinization temperature rice lines will undergo further selection for superior agronomic traits, and evaluate for yield performance and stability in intra-, inter-, and farmer-level trials.