盐节木种子萌发对温度、光照和盐旱胁迫的响应

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

以盐节木(Halocnemum strobilaceum)种子为材料,研究不同温度、光照对种子萌发的影响,以及种子萌发阶段对不同浓度Na Cl溶液和PEG-6000溶液的响应。结果表明,1)盐节木种子萌发的最适温光条件为30℃12 h黑暗/35℃12 h光照,最终萌发率达到99%。2)低浓度(0~300 mmol·L-1)的Na Cl对盐节木种子萌发不构成胁迫,中等或较高浓度(400~700 mmol·L-1)的Na Cl则显著抑制其萌发(P<0.05);随着Na Cl浓度的增加,抑制作用加剧,盐节木种子的耐盐(Na Cl)阈值和极限值分别为470.47、829.30 mmol·L-1。3)高渗透势(-0.4~0.0MPa)的PEG对盐节木种子萌发不构成胁迫,中等或较低渗透势(-1.4^-0.6 MPa)的PEG则显著抑制其萌发(P<0.05),随着外界渗透势的降低,抑制作用加剧,盐节木种子的耐旱(PEG)阈值和极限值分别为-0.75和-1.46 MPa。盐节木种子萌发时表现出较强的抗盐性和抗旱性。

The effects of light,temperature,Na Cl 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 Na Cl( 0 ~ 300mmol·L-1) did not inhibit seed germination,while medium or high concentrations of Na Cl( 400 ~ 700 mmol·L-1) significantly inhibited( P < 0. 05) seed germination whose effects increased with the increase of Na Cl concentrations. The threshold and limit values of Na Cl tolerance in H. strobilaceum seed were 470. 47 and 829. 30 mmol·L-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( P < 0. 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.