混合盐胁迫对茶花凤仙种子萌发的影响

以茶花凤仙种子为试材,将NaCl、Na_2SO_4、NaHCO_3和Na_2CO_3按1∶1∶1∶1和0∶0∶1∶1两种摩尔配比人工模拟pH值分别为9.56和10.68的盐碱混合胁迫条件,探讨混合盐胁迫对其种子萌发指标的影响,明确种子萌发期对混合盐胁迫的耐受性。结果表明:2种混合盐胁迫处理下,茶花凤仙种子初始萌发时间滞后;与对照相比,种子发芽率呈现"低促高抑"现象,而发芽势、发芽指数和活力指数均随混合盐浓度的升高而逐渐降低。解除混合盐胁迫后,pH值为9.56处理下的茶花凤仙种子仍具有一定的萌发力,而pH值为10.68处理下的种子已完全失活。茶花凤仙种子萌发阶段对2种混合盐胁迫的耐盐适宜浓度分别为68.05 mmol·L^-1,60.53 mmol·L^-1,耐盐半致死浓度分别为119.59 mmol·L^-1,101.18 mmol·L^-1,耐盐极限浓度分别为202.07 mmol·L^-1,166.22 mmol·L^-1。

Effect of Mixed Salt Stress on Seed Germination of Impatiens balsamena L.

Four single salts of NaCl,Na 2SO 4,NaHCO 3 and Na 2CO 3 were combined with ratios of 1∶1∶1∶1 and 0∶0∶1∶1 to artificially simulate the saline-alkaline mixed stresses with pH of 9.56 and 10.68,respectively.It was studied the effects of mixed salt stress on germination index of Impatiens balsamena seeds,and it was determined the tolerance of seeds to mixed salt stress at germination stage.The result showed that the initial germination time was delayed under mixed salt stress.Compared with the control,the germination rate of seeds was promoted by mixed salt stress under lower salinity,and inhibited under higher level.While the germination index,vigor index and germination potential gradually decreased with the increasing salinity.After removing mixed salt stress,Impatiens balsamena seed still had a certain germination capacity under treatment of pH 9.56,while the seeds were completely inactivated under treatment of pH 10.68.The salt-tolerance appropriate concentrations of Impatiens balsamena seed to mixed salt stress of pH 9.56 and 10.68 were 68.05 and 60.53 mmol·L^-1 respectively,and the salt-tolerance half-lethal concentrations were 119.59 mmol·L^-1 and 101.18 mmol·L^-1,and the salt-tolerance limit concentrations were 202.07 mmol·L^-1 and 166.22 mmol·L^-1,respectively during seed germination.