Salinity tolerance of rice as related to growth and physiological characteristics

Abstract

The effect of salinity of the physico-chemical characters of rice was studied to understand the physiology of salt tolerance. Salinity was observed to affect root length more drastically than shoot height. Higher salt tolerance indices (STI) and lower reductions of dry weight were recorded in salinity tolerant varieties, Pokkali and Nonabokra. At EC of 2.5 dS/m, except IR 20, the beneficial effect of salinity was reflected by increased dry matter accumulation in the shoot. The salinity tolerant varieties showed higher initial chlorophyll content and a less reduction of chlorophyll with the increase of salinity. Although N increased with the increase of salinity, the total N uptake was the highest only at EC of 2.5 dS/m, correlating well with a higher dry matter production at this level. Salt tolerance index, chlorophyll and N contents are good indicators of salt tolerance in rice.