Response of Halocnermum strobilaceum to light, temperature, salt and drought stresses during seed germination

The effects of light, temperature, NaCl and PEG-6000 on seeds germination of Halocnermum strobilaceum were estimated. The optimal conditions of temperature and light for seeds germination of H. strobilaceum was 30 ℃, dark for 12 h/35 ℃, light for 12 h which had germination rate of 99%. Low concentrations of NaCl (0～300 mmolL-1) did not inhibit seed germination, while medium or high concentrations of NaCl (400~700 mmolL-1) significantly inhibited (P0.05) seed germination whose effects increased with the increase of NaCl concentrations. The threshold and limit values of NaCl tolerance in H. strobilaceum seed were 470.47 and 829.30 mmolL-1, respectively. High osmotic potentials of PEG (-0.4~0.0 MPa) did not inhibit seed germination, while medium or low osmotic potentials of PEG (-1.4~0.6 MPa) significantly inhibited (P0.05) seed germination whose effects increased with the decrease of osmotic potentials. The threshold and limit values of PEG tolerance in H. strobilaceum seed were -0.75 and -1.46 MPa, respectively. All of these results suggested that H. strobilaceum seed had higher salt and tolerance at germination stage.