摘要
在气候箱中研究了土壤温度、气温对高山草本植物紫花雪山报春光合作用和蒸腾作用的影响。结果显示 :1 0℃～ 2 5℃土壤温度范围内 ,净光合速率和蒸腾速率及气孔导度和胞间CO2 浓度随土壤温度的变化为“单峰”曲线。“峰”值及其位置受气温影响。在 1 0℃～ 35℃气温范围内 ,净光合速率随气温的变化曲线为“单峰”型 ,蒸腾速率、气孔导度和胞间 CO2 浓度随气温升高既有增加又有减少 ,增加或是减少及变化速率与土壤温度有关。土壤温度和气温对光合作用和蒸腾作用都有影响 ,各因子对光合作用和蒸腾作用的影响受到另一因子的促进或制约。其中一因子处于不利状态 ,光合作用和蒸腾作用都将受到严重损害。土壤温度和气温分别为 2 0℃和 2 5℃时 ,紫花雪山报春叶片净光合速率最大 ,为 1 4 .67μmol CO2 · m-2 · s-1 。光合作用的最适温度范围是土壤温度 1 5℃～ 2 0℃ ,气温 2 0℃～ 2 5℃。经相关系数分析表明 :在不同气温条件下 ,土壤温度变化时净光合速率、蒸腾速率与气孔导度、胞间 CO2 浓度的相关性不同 ;在不同土壤温度条件下 ,气温变化时它们之间的相关性也不同。不同气温下土壤温度影响光合作用、蒸腾作用或不同土壤温度下气温影响光合作用。
The effect of soil and air temperature on photosynthesis and transpiration of Primula sinopurpurea ,a alpine herb,was studied in the climatic cabinet.The result showed:the variation of net photosynthetic rate (Pn),transpiration rate (Tr),stomatal conductance (SC) and internal CO 2 concentration (Ci) with soil temperature appeared as one peak curve at 10℃~25℃ soil temperature.The position and the height of the peak were related with air temperature.At 10℃~35℃ air temperature,the variation of Pn appeared as one peak curve.With air temperature increasing Tr and SC and Ci increased or decreased,increasing or decreasing depended on soil temperature.Photosynthesis and transpiration were effected by both the soil and air temperature,if one of them was at suboptimum or superoptimum,photosynthesis and transpiration would be harmed seriously.At 15℃~20℃ soil temperature and 20℃~25℃ air temperature the photosynthetic rate was highest,14.67 μmol CO 2·m -2 ·s -1 .Correlation analysis showed:when soil temperature varied correlation coefficients between Pn or Tr and SC or Ci changed at different air temperature.When air temperature varied correlation coefficients between them changed at different soil temperature.The physiological mechanism of effects of soil or air temperature on Pn and Tr varied at different air temperature or soil temperature.
出处
《西北植物学报》
CAS
CSCD
2002年第4期824-830,共7页
Acta Botanica Boreali-Occidentalia Sinica
