Salt Tolerance in Two Suaeda Species: Seed Germination and Physiological Responses

摘要

The main aim of this study is to detect the effects of NaCl, NaHCO₃ and sea salt on seed germination, seedling growth and seedling cation contents of two Suaeda species. Three germination experiments of S. corniculata and S. salsa seeds were conducted in growth chambers. The seeds were placed at three types of salt at concentrations: 0, 25, 50, 75, 100% seawater; 0, 100, 200, 300, 400, 500 mM NaCl and 0, 100, 200, 300, 400, 500 mM NaHCO₃, separately. The two species varied in their salt tolerance for germination rates and percentages and showed higher germination percentage at higher salt stress (500 mM NaCl, NaHCO₃ and 100% seawater). Some un-germinated seeds were recovered after being transferred to distilled water. The Na⁺ content in seedlings increased with the increase in stress intensity. While K⁺ content and K⁺/Na⁺ ratio decreased under NaCl and NaHCO₃ stress. K⁺ content increased in seawater treatment while reaching higher salt concentrations, due to the extra K⁺ in seawater, but there was no significant difference among the treatments with varied seawater concentrations (p<0.001). These results suggested that S. corniculata and S. salsa could be used as pioneer plants for ecological recovery and exploitation of saline and sodic soils.