Keywords: 
• Baodao banana /
• seawater /
• plasma membrane /
• osmolyte

Abstract: Seedlings of Baodao banana（ Musa acuminata L. AAA cavendish. cv. ‘Formosana’） were treated with different concentrations of seawater at different time to study the response of their plasma membrane and osmolytes to the seawater. After treated with different concentrations of seawater,Baodao banana seedlings were higher in content of proline,soluble sugar,soluble protein and MDA and higher in plasma membrane permeability under the 5% seawater treatment but significantly higher under the 10% and 20% seawater treatment than the control. At day 12 after treatment the proline content was not significantly increased under 5% seawater stress,but the 20% seawater treatment inhibited root protein synthesis due to high seawater concentration. At day 3,the leaves and roots of the seedlings under 10% seawater treatment showed significantly higher soluble sugar content（ 130% and 50% higher） than those of the control,respectively. The 20% seawater treatment caused significant damage to the plasma membrane of leaf and root,and the leaf membrane damage was reversible but root damage was irreversible. Therefore,seawater had significantly higher effect on the roots than the leaves. Low concentration（ 5%） of seawater can improve the salt tolerance of the Baodao banana seedlings to some extents,whereas high concentration（ 10% and 20%） of seawater caused salt damage to the Baodao banana seedlings. The results showed that Baodao banana can adapt to a given concentration of seawater environment by their osmotic adjustment mechanism.