【作者】 陈冠宜；

【导师】 范海；

【作者基本信息】 山东师范大学 ， 植物学， 2011， 硕士

【摘要】 本文以盐地碱蓬（Suaeda salsa L.）和小花碱茅（Puccinellia tenuiflora）为实验材料,研究不同浓度的NaCl和Na₂CO₃处理对二者种子萌发率及萌发阶段幼苗的生长状况、幼苗的生理特性、活性氧清除系统、光合特性以及PSⅡ光化学特性的影响,从而探讨NaCl和Na₂CO₃胁迫对盐地碱蓬和小花碱茅的伤害以及盐碱胁迫下盐地碱蓬和小花碱茅的光合特性。结果如下:1.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅种子萌发率、萌发阶段及幼苗期生长状况的影响盐地碱蓬和小花碱茅的种子萌发率随着盐碱浓度的增加而降低。盐地碱蓬和小花碱茅种子的萌发率在NaCl胁迫下的下降趋势明显大于在Na₂CO₃胁迫下的下降趋势。证明了渗透胁迫,而不是pH值因素,是影响盐地碱蓬和小花碱茅种子各自萌发率的主要原因。盐地碱蓬和小花碱茅在萌发阶段和幼苗期的生长状况随着NaCl和Na₂CO₃浓度的升高而变弱。盐地碱蓬受Na₂CO₃胁迫明显高于NaCl胁迫,而小花碱茅受NaCl胁迫明显高于Na₂CO₃胁迫。2.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅丙二醛（MDA）含量的影响在NaCl和Na₂CO₃胁迫下,随着盐碱浓度的升高,盐地碱蓬和小花碱茅叶片中丙二醛（MDA）的含量不断增加。在NaCl胁迫下,盐地碱蓬和小花碱茅叶片中的MDA含量的增加幅度小于在Na₂CO₃胁迫下的增加幅度。表明Na₂CO₃对盐地碱蓬和小花碱茅的胁迫更大。3.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅叶片超氧化物歧化酶（SOD）活性的影响在NaCl和Na₂CO₃胁迫下,随着盐碱浓度的升高,盐地碱蓬和小花碱茅叶片中超氧化物歧化酶（SOD）的活性表现出不同的变化趋势。在NaCl胁迫下,盐地碱蓬叶片中的SOD活性随着盐浓度的升高呈现出先升高后降低的趋势,在200mM时达到最大值,且较CK升高显著,在一定程度上说明了盐地碱蓬在200mM NaCl处理下生长最好的原因与活性氧的清除有关;小花碱茅叶片中的SOD活性随着盐浓度的升高呈逐渐下降趋势。在Na₂CO₃胁迫下,盐地碱蓬和小花碱茅叶片中的SOD活性随着Na₂CO₃浓度的升高下降趋势都很明显。4.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅叶黄素循环的影响盐地碱蓬在NaCl处理下,随着盐浓度的升高,叶黄素脱环化程度（DPS）先下降后升高,而且在300、400mM NaCl条件下均明显上升。在Na₂CO₃胁迫下,随着盐浓度的升高,叶黄素脱环化程度（DPS）逐渐升高,且75、100 mmol/L Na₂CO₃升高显著。小花碱茅在NaCl处理下,随着盐浓度的升高,叶黄素脱环化程度（DPS）逐渐升高,且400mM NaCl条件下上升显著。在Na₂CO₃胁迫下,随着盐浓度的升高,叶黄素脱环化程度（DPS）逐渐升高,且75、100 mmol/L Na₂CO₃升高显著,表明依赖于叶黄素循环的能量耗散在盐胁迫下能起到有效的保护作用。5.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅叶光合放氧速率的影响在NaCl和Na₂CO₃胁迫下,随着盐碱浓度的升高,盐地碱蓬和小花碱茅叶片的光合放氧速率表现出不同的变化趋势。盐地碱蓬在NaCl处理下,随着盐浓度的升高,光合放氧速率先升高后下降,而且在400mM NaCl条件下明显下降。在Na₂CO₃胁迫下,随着盐浓度的升高,光合放氧速率逐渐下降,且100 mmol/L Na₂CO₃下下降极显著。小花碱茅在NaCl处理下,随着盐浓度的升高,光合放氧速率逐渐降低,200、300、400mM NaCl条件下较CK下降显著,且400mM NaCl时下降极显著。在Na₂CO₃胁迫下,随着盐浓度的升高,光合放氧速率逐渐下降,且75、100 mmol/L Na₂CO₃下降显著。二者相比较,盐地碱蓬的抗盐性强于小花碱茅,而抗碱性方面小花碱茅要弱强于盐地碱蓬。6.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅叶绿素荧光参数的影响盐地碱蓬在NaCl胁迫下,Fo随着盐浓度的升高先降低后升高,Fv/Fm先增加后降低,二者变化不明显,表明在NaCl胁迫下,盐地碱蓬的光合作用中心并没有受到破坏,PSⅡ潜在光化学效率基本没受到影响。在Na₂CO₃胁迫下,Fo随着碱浓度的升高不断升高, Fv/Fm不断降低,且75、100mM Na₂CO₃时较CK变化极显著,表明在较高浓度Na₂CO₃胁迫下,盐地碱蓬的光合作用中心受到明显破坏,PSⅡ潜在光化学效率下降显著。小花碱茅在NaCl和Na₂CO₃胁迫下,Fo随着盐浓度的升高不断增加,Fv/Fm不断降低,且变化明显。表明在NaCl和Na₂CO₃胁迫下,小花碱茅的光合作用中心受到明显破坏,PSⅡ潜在光化学效率下降显著。7.NaCl和Na₂CO₃对盐地碱蓬和小花碱茅PSⅡ光化学特性的影响Wk表示K相可变荧光占（FJ-FO）振幅的比例,Wk升高表明反应中心受到损伤,在NaCl处理下,随着盐浓度的升高盐地碱蓬的升高幅度小于小花碱茅的升高幅度。而在Na₂CO₃处理下,随着盐浓度的升高小花碱茅的升高幅度较小。Sm表示从2ms到tFm时间内QA被完全还原所需要的能量,Sm降低表明反应中心的电子传递能力下降;N表示从2ms到tFm时间内QA的氧化还原次数,N降低表明电子传递能力下降,反应中心的开放程度降低;VJ表示照光2ms有活性的反应中心的关闭程度;在NaCl处理下,随着盐浓度的升高盐地碱蓬Sm和N的下降幅度小于小花碱茅的下降幅度,并且VJ的升高幅度也小于小花碱茅;而在各盐度的Na₂CO₃处理下,小花碱茅Sm、N、VJ的变化幅度小于盐地碱蓬。盐地碱蓬随着NaCl浓度的升高,单位叶面积有活性的反应中心数（RC/CSo）先升高后降低,导致单位反应中心吸收的光能（ABS/RC）,用于还原QA的能量（TRo/RC）,用于电子传递的能量（ETo/RC）,耗散掉的能量（DIo/RC）和反应中心之间激发能的传递的参数（dVG/dto）先降低后升高,而小花碱茅随NaCl浓度的升高,RC/CSo不断降低,ABS/RC、TRo/RC、ETo/RC、DIo/RC和dVG/dto不断降低,且变化幅度比盐地碱蓬大;另外,以吸收光能为基础的性能指数（PIABS）和以吸收光能为基础的推动力（D.F.）盐地碱蓬的下降幅度小于小花碱茅的下降幅度。而在各盐度的Na₂CO₃处理下,小花碱茅反应中心各参数的变化幅度小于盐地碱蓬。从PSII的供体侧,受体侧和反应中心的各参数变化幅度可以推测盐地碱蓬的抗盐性稍强于小花碱茅,而盐地碱蓬的抗碱性要稍弱于小花碱茅。总之,盐地碱蓬和小花碱茅种子萌发率主要受到渗透胁迫的抑制,pH值对二者种子萌发的影响很小;通过对盐地碱蓬和小花碱茅幼苗期的生理指标和光合指标的研究发现盐地碱蓬的抗盐性要稍强于小花碱茅,而小花碱茅的抗碱性要稍强于盐地碱蓬。更多还原

【Abstract】 This study tries to explore the impact of NaCl and Na₂CO₃ stress on the growth of Suaeda salsa L. and Puccinellia tenuiflora,through evaluating the effects on seed germination, growth of seedling conditions, physiological characteristics, thermal dissipation, as well as metabolism of reactive oxygen species and photochemical characteristics of PSⅡ. The main results are as follows:1. Effect of different concentrations of NaCl and Na₂CO₃ on seed germination , the growth of seedling conditions during germination stage and the growth in Suaeda salsa L. and Puccinellia tenuifloraGermination rate of Suaeda salsa and Puccinellia tenuiflora decreased with both of the salts concentrations. The seed germination of Suaeda salsa and Puccinellia tenuiflora under NaCl stress decreased significantly greater than that under Na₂CO₃ stress, indicating that osmotic stress, rather than pH stress, was the main reason for germination inhibition in Suaeda salsa and Puccinellia tenuiflora under both NaCl and Na₂CO₃ stress.The growth of seedling conditions during germination stage and the growth of Suaeda salsa and Puccinellia tenuiflora became weaker with the increase of NaCl and Na₂CO₃ concentrations. And the growth conditions of Suaeda salsa under NaCl stress was better than under Na₂CO₃ stress, On the contrary, the growth conditions of Puccinellia tenuiflora under NaCl stress was worse than under Na₂CO₃ stress.2.Effect of different concentrations of NaCl and Na₂CO₃ on the MDA content of Suaeda salsa L. and Puccinellia tenuiflora.Under NaCl and Na₂CO₃ stress, the MDA content of Suaeda salsa and Puccinellia tenuiflora leaves increased with NaCl and Na₂CO₃ concentrations. But the MDA content of Suaeda salsa and Puccinellia tenuiflora leaves increases less under NaCl than under Na₂CO₃ stress, showing that Na₂CO₃ stress was more seriouse than NaCl stress.3.Effect of different concentrations of NaCl and Na₂CO₃ on the SOD activity in the leaves of Suaeda salsa L. and Puccinellia tenuiflora.Under NaCl and Na₂CO₃ stress, with the salt concentration increasing, the SOD activity of Suaeda salsa and Puccinellia tenuiflora showed different trends. Under NaCl stress, the SOD activity of Suaeda salsa increased firstly and then decreases with the salt concentrations, and peaked at 200 mmol/L, but still higher than CK at 400mM NaCl. For Puccinellia tenuiflora, the SOD activity decreases continuously with the NaCl concentrations. Moreover, under Na₂CO₃ stress, the SOD activity of Suaeda salsa and Puccinellia tenuiflora both decreased significantly with Na₂CO₃ concentrations.4.Effect of different concentrations of NaCl and Na₂CO₃ on the xanthophyll cycle of Suaeda salsa L. and Puccinellia tenuiflora.Under NaCl treatment, with the salt concentration increasing, the de-epoxidation degree of xanthophyll cycle （DPS） of Suaeda salsa decreased firstly and then increased, and significant increased under 300 and 400 mmol/L NaCl. Under Na₂CO₃ stress, the DPS increased gradually but significantly under 75 and 100 mmol/L Na₂CO₃. As for Puccinellia tenuiflora, the DPS increased gradually under NaCl and Na₂CO₃ stress, and increased significantly under 400mM NaCl and 75, 100 mmol/L Na₂CO₃, respectively. All the results implied that the de-epoxidation degree of xanthophyll cycle can play an effective protection on Suaeda salsa and Puccinellia tenuiflora under salt stress.5.Effect of different concentrations of NaCl and Na₂CO₃ on the photosynthetic oxygen evolution rate of Suaede salsa L.and Puccinellia tenuiflora.Under NaCl and Na₂CO₃ stress, with the salt concentration increasing, Suaeda salsa and Puccinellia tenuiflora photosynthetic oxygen evolution rate showed different trends. As for Suaeda salsa under NaCl treatment, the photosynthetic oxygen evolution rate increases first and then decreases with NaCl concentrations, and decreased significantly under 400mM NaCl. Under Na₂CO₃ stress, however, with the increase of Na₂CO₃ concentration, the photosynthetic oxygen evolution rate decreases gradually and significantly under 100 mmol/L Na₂CO₃. As for Puccinellia tenuiflora under NaCl stress, the photosynthetic oxygen evolution rate decreased gradually and significantly under 200, 300 and 400 mmol/L NaCl. Under Na₂CO₃ stress, the trend was the same, with the increase of Na₂CO₃ concentration; the photosynthetic oxygen evolution rate gradually increases, and decreases significantly under 75 and 100 mmol/L concentrations. Comparingly, the salt tolerance of Suaeda salsa is stronger than that of Puccinellia tenuiflora, and the alkali tolerance of Suaeda salsa is weaker than that of Puccinellia tenuiflora.6.Effect of different concentrations of NaCl and Na₂CO₃ on the Chlorophyll fluorescence parameters of Suaeda salsa L. and Puccinellia tenuiflora.Under NaCl stress, Fo of Suaeda salsa decreased firstly and then decreased, while Fv/Fm of Suaeda salsa increased firstly and then decreased, but all not significant, indicating that the photosynthesis centers of Suaeda salsa were not damaged by NaCl, the potential photochemical efficiency of PSⅡwas not obviously affected. However, under Na₂CO₃ stress, Fo increased continuously with the alkali concentrations, and Fv / Fm decreased continuously simultaneously, indicating that the reaction center was affect by high Na₂CO₃ concentrations. Under NaCl and Na₂CO₃ stress, Fo of Puccinellia tenuiflora increased and Fv/Fm decreased continuously and significantly with concentrations, Indicating that photosynthesis center of Puccinellia tenuiflora was significantly damaged under NaCl and Na₂CO₃ stress, the potential photochemical efficiency of PSⅡdecreased significantly.7.Effect of different concentrations of NaCl and Na₂CO₃ on the photochemical characteristics of PSⅡin Suaeda salsa L. and Puccinellia tenuiflora.Wk accounts for K-phase variable fluorescence （FJ-FO） amplitude ratio, it can indicate that the reaction center has been damaged with the salt concentration increasing.The Wk of Suaeda salsa increases more than it of Puccinellia tenuiflora with the NaCl concentration increasing.On the contrary, the Wk of Suaeda salsa increases less than it of Puccinellia tenuiflora with the Na₂CO₃ concentration increasing.With the NaCl treatment, Sm, N and VJ of Suaeda salsa change less than them of Puccinellia tenuiflora, but Sm, N and VJ of Suaeda salsa change more than them of Puccinellia tenuiflora with the Na₂CO₃ concentration increasing. With the NaCl treatment, the RC/CSo of Suaeda salsa increased firstly and then decreased slightly at 300 and 400 mM NaCl compared with CK, and the change was not obvious. Meanwhile, ABS/RC,TRo/RC,ETo/RC,DIo/RC and dVG/dto decreased firstly and then increased slightly at 300,400 mmol/L NaCl. But them of Puccinellia tenuiflora showed opposite tendency.And them of Suaeda salsa changed less than them of Puccinellia tenuiflora. On the contrary, them of Suaeda salsa changed more than them of Puccinellia tenuiflora with the Na₂CO₃ concentration increasing.Under NaCl and Na₂CO₃ stress, it is indicated that the salt tolerance of Suaeda salsa is slightly stronger than it of Puccinellia tenuiflora and the alkali tolerance of Suaeda salsa is slightly weaker than it of Puccinellia tenuiflora from the provide side, receptor side and the reaction center of PSII.In short, seed germination of Suaeda salsa and Puccinellia tenuiflora were inhibited mainly by osmotic stress, not pH. Furthermore, the salt tolerance of S. salsa was slightly stronger than Puccinellia tenuiflora and the alkali tolerance of Puccinellia tenuiflora was slightly stronger than S. salsa by the study of physiological and photochemical characteristics of Suaeda salsa and Puccinellia tenuiflora.更多还原