Comparison of Damage of Iso-osmotic Stress of NaCl and PEG on Maize Seedling

[Objective] The aim was to study the changes of main physiological indexes of maize seedling under iso-osmotic stress of NaCl and PEG.[Method] The iso-osmotic stress of NaCl and PEG with osmotic potential of-0.5,-0.6,-0.7,-0.8 Mpa were taken to treat the maize seedlings,the relative water content in leaves,chlorophyll content,biomass,plant height and electrolyte leakage of leaf cells of seedlings were measured after 72 h of the treatment.[Result] With the increase of NaCl and PEG concn.,the chlorophyll content firstly increased and then decreased,the relative water content in leaves,chlorophyll content,biomass,plant height and K content in above-ground part and under-ground part of maize seedlings were all decreased gradually,but the electrolyte leakage of leaf cells increased gradually.In treatment with PEG,the Na+ content in above-ground part of seedling was increased with the increase of PEG concn.,but that in under-ground part decreased.The relative water content of seedling leaves,chlorophyll content,biomass and plant height of seedlings under NaCl stress were all higher than those under PEG stress.[Conclusion] The response of maize to NaCl and PEG stress were 2 different processes.