Salt tolerance in the halophyte Suaeda nudiflora MOQ.: Effect of NaCl on grwoth, ion accumulation and oxidative enzymes

The effect of NaCl (0 – 680 mol m⁻³) salinity on growth, ion accumulation and enzyme activities were studied in a dicotyledonous halophyte Suaeda nudiflora Moq. Plant growth was optimal between 170–340 mol m⁻³ NaCl with maximal growth (fresh and dry mass) at 340 mol m⁻³. Water contributed to a large proportion of increase in fresh mass. The accumulation of cations was greater in leaves than in shoot or root. Na⁺ and Cl⁻ contributed substantially to dry mass. Salinity treatments decreased the concentration of K⁺ in leaves. The Ca²⁺ content and Na⁺/K⁺ ratio increased steadily with salinity. Salt stress stimulated peroxidase and superoxide dismutase activities, whereas acid phosphatase and ATPase showed salt sensitivity. The changes in enzyme activities and thier possible roles in salt tolerance of Suaeda nudiflora have been discussed.