Salt Tolerance in Rice Cultivars and Changes in Sodium and Potassium Ions

Abstract

Salinity is an environmental stress that limits growth and development in plants. Due to high salinity in Khuzestan soils it is necessary to identify cultivars with appropriate yield that are compatible with Khuzestan conditions. This experiment was done to evaluate three rice cultivars for salinity tolerance at seedling stage by measuring the absorption of sodium and potassium ions and the ratio of Na⁺/K⁺ in the shoots and roots of the rice crop. Experiments were carried out under controlled conditions and in hydroponics culture media. Treatments included three rice cultivars (Amol3, Anbouri and Shahpasand) and five levels of salinity (control: without salt addition, salinity levels of 25, 50, 75 and 100 mM NaCl) according a factorial experiment based on completely randomized design with three replications. Acid digestion method was used to measure sodium and potassium ions in plant tissues. The amount of sodium in the root and also shoot of three cultivars showed a significant difference (p≤ 0.05, p≤ 0.01). Shahpasand showed the lowest amount of sodium in its shoots compare to the other two varieties. The results showed that Na⁺/K⁺ ratio was significantly different in three cultivars under salinity conditions. Shahpasand showed the lowest and Anbouri showed the highest ratios. Shahpasand can be considered as a salt tolerant cultivar and also a salt tolerant parent in hybridization and breeding programs for producing new salt tolerant cultivars.