Abstract: 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(F_o),maximum fluorescence(F_m),PSⅡprimary light energy conversion efficiency(F_v/F_m) and the PSⅡprimary light energy conversion efficiency(F_v/F_o) 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.

Key words: Elymus sibiricus, NaCl stress, Germination characteristics, Fluorescence characteristics

摘要： 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(F_o)、最大荧光(F_m)、可变荧光(F_v)、PSⅡ光化学效率(F_v/F_m)和PSⅡ潜在活性(F_v/F_o)值均呈降低趋势,量子产量(Yield)与荧光光化学淬灭系数(qNP)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。

关键词: 老芒麦, NaCl胁迫, 发芽特性, 荧光特性