盐胁迫对沙冬青幼苗生长与生理特性的影响

Effects of Salt Stress on Growth and Physiological Characteristic of Ammopiptanthus mongolicus seedlings

水培条件下,对沙冬青幼苗以不同浓度的NaC l溶液进行处理,并测定其相关生理指标。结果显示:随着盐浓度的增加,叶绿素含量与叶绿素荧光参数(Fv/Fo和Fv/Fm)逐渐降低,丙二醛含量升高。超氧化物歧化酶(SOD)和过氧化物酶(POD)活性随着盐浓度的升高表现出先上升后下降的趋势,0.7%盐胁迫下的幼苗POD酶活性最高,1.0%和1.3%盐胁迫下的酶活性逐渐降低,而过氧化氢酶(CAT)的活性呈持续上升趋势。各处理渗透调节物质脯氨酸的含量较对照明显增加,可溶性糖含量在根中升幅较大,叶片增幅不明显。幼苗死亡率也随着胁迫程度的加剧而升高,当浓度达到1.0%和1.3%时幼苗死亡率较高,分别达到了53.33%和76.67%。研究表明,低浓度盐胁迫下(0.7%以下),沙冬青幼苗表现出较强的抗性;当盐浓度升高到1.0%和1.3%时,其生长受到严重影响。

The Ammopiptanthus mongolicus seedlings were treated with different NaCl concentrations under water culture. Morphological indices and physiological indices were measured and analyzed. The result indicated that： Along with the increase of salt concentrations, the chlorophyll contents and the fluorescent parameters （FiFo and Fv/Fm ） decreased, the MDA contents increased. The activity of superoxide dismutase （SOD） and peroxidase （POD） first rose and then decreased as the salt concentration increased; the seedlings under 0. 7% NaCl stress had the highest POD activity, the POD activity gradually decreased when the concentration rose to 1.0% and 1.3%. The contents of proline increased evidently with the increasing of NaCI concentrations, but the soluble sugar only increased in roots. With the NaCl stress degree intensifying, the death rate also increased, and reached 53.33% and 76.67%. It was thus suggested that the seedlings treated with 0.4% - 0. 7% NaCl showed strong resistance; when treated with 1.0% -1.3% NaC1, the seedlings were badly influenced.