Salinity Induced Metabolic Changes in Rice (oryza Sativa L.) Seeds during Germination

Six inbred lines of rice exhibiting differential tolerance to salinity were exposed to 0, 50, 75, 100 and 200mM NaCl for 24, 48, 72 and 96 h. The salinity induced metabolic changes (solute leakage, K efflux and α-amylase activity) were studied during germination. Germination of rice seeds was not affected by NaCl concentration less than 100mM. At higher salinity levels (100 & 200mM NaCl), a delay of 3-6 days in germination was observed. In the present study, comparatively higher values of solute leakage were observed in those lines in which germination was comparatively affected more adversely (sensitive). Sodium chloride reduced α-amylase activity in germinating rice seeds to varying degree even at low NaCl concentrations (50 & 75mM), where germination was not affected greatly. The tolerant lines exhibited higher enzymatic activity than the sensitive ones.