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作 者 ：刘强1；王庆成2；王占武1

期 刊 ：植物研究 2014年 34卷 6期 页码：765-769

关键词：木本植物；NaHCO3胁迫；光合；生理响应；

Keywords:woodyplant, NaHCO3stress, photosynthesis, physiologicalresponse,

摘 要 ：以5个抗盐性不同的树种白榆、新疆枸杞、南蛇藤、小叶丁香、樟子松的一年生实生苗为实验材料，研究光合生理参数作为植物抗盐性评价指标的有效性。结果表明：5个树种的抗盐性由强到弱依次为新疆枸杞、白榆、南蛇藤、小叶丁香、樟子松。5个树种对NaHCO₃胁迫有一致的光合响应，即净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）、细胞间隙CO₂浓度(C_i)和气孔限制值(L_s)等光合参数均呈下降趋势。与对照相比，重度胁迫下白榆、新疆枸杞、南蛇藤、小叶丁香、樟子松P_n分别下降33.97%、31.40%、54.97%、71.18%和72.25%，5个树种苗木P_n下降幅度顺序为樟子松>小叶丁香>南蛇藤>白榆>新疆枸杞；重度胁迫下5个树种苗木T_r分别比对照下降36.18%、48.49%、46.07%、53.55%和71.82%，5个树种苗木T_r下降幅度顺序为樟子松>小叶丁香>新疆枸杞>南蛇藤>白榆；重度胁迫下5个树种苗木G_s分别比对照下降58.73%、72.16%、19.82%、48.22%和7415%，5个树种苗木G_s下降幅度顺序为樟子松>新疆枸杞>白榆>小叶丁香>南蛇藤。研究表明，在低NaHCO₃胁迫下白榆和新疆枸杞叶片光合下降的原因是气孔限制，在高NaHCO₃胁迫时，则为非气孔限制；南蛇藤和樟子松为气孔限制因素；小叶丁香为非气孔因素。在NaHCO₃胁迫条件下，抗性较强的白榆和新疆枸杞净光合速率降低的程度明显小于抗性较弱的小叶丁香和樟子松。

Abstract:We investigated the effectiveness of photosynthetic characteristics as an evaluation index of salt tolerance in five trees differing in tolerance to salt stress. The salt tolerance rank of the five trees is Lycium dasystemum>Ulmus pumila>Celastrus orbiculatus>Syringa microphylla>Pinus sylvestris var. mongolica. Five woody plants responsed identically to NaHCO₃ stress, that is, net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), intercellular space CO₂ concentration (C_i) and stomata limitation (L_s) all decline obviously. P_n decreasing scale of five trees was P.sylvestris var. mongolica>S.microphylla>C.orbiculatus>U.pumila>L.dasystemum. T_r decreasing scale of five trees was P.sylvestris var. mongolica>S.microphylla>L.dasystemum>C.orbiculatus>U.pumila. G_s decreasing scale of five trees was P.sylvestris var. mongolica>L.dasystemum>Ulmus pumila>S.microphylla>C.orbiculatus. According to the changes of photosynthesis parameters of five seedlings, under lower stress intensity, the main factor leading to decreasing in photosynthesis rate of U.pumila and L.dasystemum was stomatal limitation, while there was non-stomatal limitation under higher stress intensity. The main factor leading to decreasing in photosynthesis rate of C.orbiculatus and P.sylvestris var. mongolica was stomatal limitation. Non-stomatal limitation was the main factor leading to decreasing in photosynthesis rate of S.microphylla. The more salt-tolerant U.pumila and L.dasystemum had a less decreasing scale of photosynthesis rate than that of S.microphylla and P.sylvestris var. mongolica.

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