EFFECT OF SODIUM-CHLORIDE ON WATER RELATIONS AND SOME ORGANIC OSMOTICA IN ARID ZONE PLANT-SPECIES MELILOTUS-INDICA (L) ALL

Two populations of Melilotus indica (L.) All. (a salt tolerant and a n on-tolerant, IM-83) were grown for 42 days in sand culture salinized w ith 0 (control), 80, 160, and 240 mol m-3 NaCl. The salt tolerant popu lation produced significantly greater plant dry biomass than the non-t olerant population. The salt tolerant population maintained low leaf o smotic potential and high turgor potential compared with that of the n on-tolerant line. The salt tolerant population maintained low leaf osm otic potential and high turgor potential compared with that of the non -tolerant line. The considerably low leaf osmotic potential of the sal t tolerant population can be easily related to its high contents of le af soluble sugars, free amino acids and proline. Of these parameters s oluble sugars played a major role in lowering the osmotic potential of the salt tolerant population and hence seemed to have contributed par tly to its high salt tolerance.