EFFECT OF SODIUM-CHLORIDE ON GROWTH, PHOTOSYNTHESIS AND MINERAL IONS ACCUMULATION OF DIFFERENT TYPES OF RICE (ORYZA-SATIVA L.)

Growth, photosynthesis and mineral ions accumulation of aromatic small grain, local coarse grain and HYV types of rice were evaluated under saline conditions. Three cultivars from each type were subjected to 0, 50, 100, 150 and 200 mM NaCl concentrations. After three weeks of 200 mM NaCl application only Pokkali and Kalobail, both belonging to the local coarse grain type and IPK 37011 of the HYV type were able to sur vive. Plant height, green leaf area, leaf weight, shoot and root growt h were seriously decreased by salinity. However, leaf area was decreas ed more than other growth parameters. In general aromatic small grain type showed higher salt-sensitiveness in relation to growth than other types of rice. Photosynthesis (Pn) was decreased by salinity and appa rently stomatal resistance was partially responsible for the decreased Pn. Kalijira, an aromatic small grain cultivar, showed serious reduct ion in Pn, especially at the 150 mM NaCl level. Na accumulation was in creased while K accumulation was decreased by salinity in all types. S alt tolerant cultivars in all types of rice accumulated less Na and mo re K than susceptible ones. The K/Na ratio was also higher in tolerant cultivars. Ca and Mg concentrations were decreased by salinity althou gh not all the cultivars showed clear accumulation patterns as observe d for Na and K. As HYV and local coarse grain types of rice in general showed high salt tolerance, a comprehensive breeding programme should be of value for the improvement of salt tolerance of aromatic small g rain rice which has a high demand in rice importing countries.