Salinity-induced variation in physiological and biochemical profiles of aromatic rice genotypes

salinity-induced variations in aromatic rice

Abstract

The aromatic rice is generally low-yielding and prone to abiotic stress, especially the salinity, which hinders yield and quality drastically. This experiment was conducted to assess the physiological and biochemical profiles of aromatic rice genotypes under salt stress. Two aromatic rice genotypes such as PK31 and PK37 were cultured under 0, 4, 6, 8, and 10 dsm-1 salinity for both tillering (Ts) and panicle initiation (PI) stages. The study employed in a factorial completely randomized design with three replications. The results indicated that salinity stress severely affected the physiological, biochemical profiles, and yield attributes of PK31 than PK37, particularly at the TS. Plant height, stem elongation rate, chlorophyll fluorescence (Fv/ Fm), shoot and root dry weight, fertile grains, grain weight, total dry matter, and harvest index decreased significantly with increasing salinity. At 10 dS m⁻¹, plant height declined to 60.00 cm in PK31 and 66.78 cm in PK37 at Ts. Proline accumulation increased markedly with salinity, reaching 2.06 µmol g⁻¹ in PK37 compared with 1.68 µmol g⁻¹ in PK31. Chlorophyll fluorescence decreased from 0.811 under control to 0.614 at 10 dS m⁻¹ in PK37, while PK31 declined to 0.519. Grain weight at TS was completely lost at 10 dS m⁻¹ in both genotypes. sodium accumulation in shoots, roots, and grains increased with salinity, with higher accumulation in PK31. Overall, PK37 exhibited greater salinity tolerance than PK31 through better physiological performance, lower sterility, and higher yield stability under saline conditions.

Ann. Bangladesh Agric. 30(1): 33-55