DOI: 10.36347/sjavs.2017.v04i04.001

Pages: 126-131

Salinity becomes a serious concern when soluble salts occur in excessive concentrations in the soil or water. NaCl is the most common salt causing salinity stress. Salinity is a major yield-reducing factor in coastal and arid irrigated rice production systems. Selection of salt tolerant rice varieties has huge impact on global food supply chain. Therefore three rice varieties namely ‘Pachaiperumal’, ‘At 307’, ‘At 308’ were tested in a pot experiment to find out their responses against salt stress in terms of plant height, shoot and root dry weight. The experiment was conducted using polyethylene bags and was laid out in the Factorial Completely Randomized Design with six treatments and four replications. Salt stress was imposed for the three weeks old rice seedlings after transplanting them in the polyethylene bags which were filled with saline soil (EC 6.6 dSm-1). Non saline soil (1.8 dSm-1) was used as the control treatment. The saline soil was collected from a saline tract of Batticaloa district. Plant height, Root and shoot dry weights and yield of the tested cultivars were significantly(P<0.05) reduced by salinity. Rice cultivar “At 307” showed the highest plant height (68.5 cm, 86.3 cm and 82.38 cm) during the growth stages respectively when exposed to salinity and the lowest plant heights (52.1,69.8 and 66.6) were found in “Pachaiperumal” under salt stress. Cultivar “At 307” showed the highest root dry weights (0.4 g, 10.1 g and 26.3g) when exposed to salinity during the growth stages and the lowest weights (0.1g, 5.1g and 19.4g) were found in “Pachaiperumal”. The highest shoot dry weight (0.21g, 26.1g, and 40.2g) was recorded in “At 307” meanwhile lowest shoot dry weight (0.8g, 12.7g, and 24.4g) was observed in “Pachaiperumal” under the saline condition. The highest yield (2.2 t.ha-1) was obtained in “At 307” and the lowest one (0.4 t.ha-1) was recorded in “Pachaiperumal” under saline condition. Thus the physiological responses of rice plants to salinity at