Abstract: The study concerns with the relative electric conductance, O^-₂ produce-rate, H₂O₂ content, and SOD, POD and CAT activity of P. tenuiflora seedlings stressed by 0~1.0% Na₂CO₃ for 1d. The results showed that the cell membrane, O^-₂ produce-rate, H₂O₂ content, defensive enzymes activity are increased along with the prick up of low density salt stress, but specific change rule of that is relevant to the saline stress intensity and to the extent of the plasma membrane of seedlings was harmed, and the character of the relationship is different.

Key words: Puccinellia tenuiflora, relative electric conductance, O^-₂ produce-rate, H₂O₂ content, defensive enzymes activity