Status of sodium-potassium as a basis of salinity tolerance in rice

An experiment was conducted in polythene lined earthen pots with three rice varieties namely PUSA-BAS 1, CSR 13 and CSR 10 treated with five levels of salinity (control, 50, 75, 100 and 150 mM NaCl). The analysis of sodium, potassium content of plants and their ratio at different phenological stages of crop growth indicated that, the increase in salinity levels enchanced the sodium content with concomitant depletion in potassium irrespective of varieties. At varietal level, the sensitive Pus a-BAS 1has higher sodium content coupled with low potassium content compared to moderately tolerant (CSR 13) and tolerant (CSR 10) varieties which were having higher potassium and lower sodium, and which might have imparted them tolerance to salinity.