NaCl胁迫对老芒麦种子发芽及幼苗荧光特性的影响

Effect of NaCl Stress on Germination and Fluorescence Characteristics of Elymus sibiricus Seed

采用不同浓度NaCl溶液(0,100,150,200,250 mmol.L-1)处理老芒麦(Elymus sibiricus)种子,通过种子发芽特性和幼苗荧光特性的变化,研究其种子和幼苗对盐胁迫的反馈机制,为老芒麦在盐碱地的建植提供参考。结果表明:不同NaCl浓度处理对老芒麦种子发芽特性具显著影响,老芒麦种子的发芽率、根长、苗长、发芽指数和活力指数均随NaCl浓度的升高而降低;不同NaCl浓度处理显著影响老芒麦幼苗叶绿素荧光特性,随着NaCl浓度的升高,幼苗叶片初始荧光(Fo)、最大荧光(Fm)、可变荧光(Fv)、PSⅡ光化学效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)值均呈降低趋势,量子产量(Yield)与荧光光化学淬灭系数(qP)无明显变化;随NaCl浓度增加非光化学淬灭系数(qNP)呈先升后降的趋势,当NaCl浓度为200 mmol.L-1时qNP值开始降低。

In order to provide information on seed germination and establishment,the effects of salt stress on germination and fluorescence characteristics of Elymus sibiricus seed were studied with different NaCl concentrations（0,100,150,200,250 mmol/L） in seed germinators.Results show that：（1）Seed germination percentage,root and shoot lengths,germination index,and vigor index all decreased as NaCl concentration increased.（2）Leaf initial fluorescence（Fo）,maximum fluorescence（Fm）,PSⅡprimary light energy conversion efficiency（Fv/Fm） and the PSⅡprimary light energy conversion efficiency（Fv/Fo） showed a declining trend as NaCl concentration increased.However,quantum yield and fluorescence efficiency of photochemical quenching（qP） had no significant changes.As the non-photochemical quenching（qNP） increased with the NaCl concentration increase,there is a decline when the NaCl concentration reaches 200 mmol/L.These results indicate that NaCl treatment may cause detrimental seedling growth of Elymus sibiricus.