SALT STRESS AFFECTS THE AGRONOMIC TRAITS, PHYTIC ACID, AND AROMA OF RICE (Oryza sativa L.) M1 MUTANT LINES

Salinity is one of the main abiotic stresses affecting yield stability and rice production. In our previous study, the M1 lines of two rice cultivars, namely, HATRI-192 (G1) and HATRI-62 (G2), were developed by using different concentrations (0.1, 0.5, and 1.0 mM) of methyl salicylate (MeSA). This study aimed to evaluate the effects of different levels of salt stresses on the agronomic traits, phytic acid content, and aroma of M1 mutant lines developed from HATRI-192 and HATRI-62. A total of 250 M1 seeds of both rice cultivars were germinated and screened for salinity at various NaCl levels (6, 8, 12, 15, and 17 dS/m) at the seedling stage and later evaluated for agronomic traits, phytic acid content, and aroma at the reproductive stage. M1G1-12, the M1 line of cultivar HATRI-192 treated with 0.5 mM MeSA, had the highest filled grain per panicle and grain yield per plant and an aromatic score of 1 at 12 dS/m as compared with the control. M1G2-8, the M1 plant of HATRI-62 treated with 0.1 mM MeSA, had the highest plant height (96 cm) and grain yield per plant (35.9 g) at 8 dS/m. The M1 seeds of cultivar HATRI-192 treated with 0.1 mM MeSA and those of cultivar HATRI-62 treated with 0.5 mM MeSA had low phytic acid contents at 15 dS/m. Overall, 6 and 13 M1 lines of cultivars HATRI-192 and HATRI-62, respectively, had aromatic scores of 1 to 2 in terms of phenotypes. Results revealed that M1 lines under salinity conditions had higher values for grain yield and its components, phytic acid content, and aroma than their parental cultivars. These pieces of relevant information can be utilized to develop salt-tolerant rice cultivars with high yielding potential and good quality.