In order to study salt tolerance in rice (Oryza sativaL.) seven genotypes consisting land races, pure and improvement lines were tested for their salt tolerance at two levels of salinity, 8 dS m-1 Electrical Conductivity (EC) and tap water as control. Completely randomized block design with three replications. Cultivars of rice were screened for salinity tolerance at seedling stage. Data taken 6 weeks after salt application were reported and traits including root and shoot length and dry weights, biomass, K+ percentage, Na+ percentage, Na+/K+ ratio, Chlorophyll Index (CI) and leaf area were measured. However, with time, salt injury symptoms were clearly visible in all plants growing in all levels of salt and showing different symptoms. The degree of injury was greater in the highest salt concentration (8 dS m-1). The symptoms appeared mostly in older leaves and the upper portion of the leaves rolled and withered away. Salt injury symptoms varied with concentration of salt and between cultivars. The relative salt sensitivity of cultivars was not consistent across salt levels indicating genotypes differences in threshold levels of salt tolerance. All plant parameters decreased significantly in all genotypes with increasing salinity. Potassium/sodium ratios of the youngest three leaves (K/Na) were determined by flame photometry at the late vegetative stage. The chlorophyll index, leaf area, roots and shoot length, dry weights and biomass decreased significantly in all genotypes of rice.
F. Gholizadeh and S. Navabpour, 2011. Effect of Salinity on Morphological and Physiological Characteristics in Correlation to Selection of Salt Tolerance in Rice (Oryza sativa L.). International Journal of Agricultural Research, 6: 780-788.