The effect of salinity was influenced by various parameters including systems of salt application, variety, salts, duration of salinity and leaf position. The effect of sali nity in Oryza sativa L., as in barley, was influenced by methods of salt application. e M-67 barley, M aratelli rice were salt susceptible and salt res istant under foliar and root treatm ents respectively on a shoot fresh weight basis but Maratelli on dry weight basis as well. However the opposite was true fo r Moroberekan. High accumulation of ions cause dehydration of tissues leading to ion toxicity and low turgor. Transpirational bypass flow was not a major pathway for Na+ transport in these varieties because there was a negative rela tionship between fluorescence a nd Na+ concentration in the varieties. Ion concentrations were varia ble and low Na+ and high e r concentrations were observed in all varieties and in RILs (eo39 x Moroberekan). Although e r concentrations were higher than Na+ in rice, it is not clear w hi ch is more toxic. Salt was toxic to parental varieties and 170 recombinant inbred lines from F8 generation (eo39 x Moroberekan) on shoot fresh weight and res istance score basis. In general, Morobere kan had higher accumu la ti on of ions particularly Na+ a nd e r than Maratelli and eo39 under salinity. Maratelli had earlier anthesis than Moroberekan. There were s ignificant negative correlations for e r , Na+ a nd the sum (Na+ +KJ w ith resistance score, SFW and water content under salinity. Na+ was significantly but negatively correlated w ith SOW under salinity. A significant and negative correlation was found between the s um a nd water content at later stages of salinity. Various QTL for physiological and growth traits were detected on different chromosomes of rice. Marker RZ276, and the region around it on chromosome l is important for salt to lerance in rice because of the presence of consistent QTL for Na+ accumulation.