Seed germination and seedling growth of Suaeda salsa under salt stress

The effect of increasing concentrations (0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.6 mol 1(-1)) of different salts (Na2SO4, Na2CO3, MgSO4, NaCl, MgCl2) in solution and soil extract solutions of comparable osmotic potentials on: germination of Suaeda salsa seeds was studied. Seed germination decreased significantly with increased salinity. Germination,inhibition was in the following order: MgCl2 > Na2SO4 > Na2CO3 > NaCl > soil extract solution > MgSO4. Non-germinated. seeds under all salt treatments recovered completely when transferred to distilled water, indicating that there was little specific ion effect on seed viability. Seedling growth was studied. under different levels of NaCl salinity (0, 0.05, 0.1, 0.2, 0.4 mol 1(-1)) stress.-Low levels of salinity (0.05-0.1 mol 1(-1)) increased seedling growth, while high levels (> 0.2 mol 1(-1) NaCl) inhibited the growth significantly. Under salt stress, the leaves accumulated high levels of proline, whereas their soluble sugar content decreased with an,increase in salinity. Na+ content in leaves, stems and roots increased with salinity. Ions were mostly accumulated in the shoot, especially in leaves. Under the highest level of salinity.(0.4 mol 1(-1) NaCl), Na+ accounted for more than 91.6% of the ions in leaves, 92.6% in stems and 84.1% in roots. Inorganic ions, especially Na+, were more important than organic solutes in the osmoregulation in S. salsa to adapt to a saline environment