摘要
在人工环境下测定了不同辐射强度，不同温度和不同水分状况下梭梭幼苗和白梭梭幼苗的净光合速率和蒸腾速率，以及水分胁迫下两种梭梭同化枝水势和含水量。实验结果表明：（１）两种梭梭光合作用和蒸腾作用对辐射强度的依赖是不同的，梭梭净光合速率和蒸腾速率随辐射强度的增加而上升的趋势明显低于白梭梭。两种梭梭幼苗在无光照对仍维持较高的蒸腾速率。（２）白梭梭的平均蒸腾系数低于梭梭，证明白梭梭能比梭梭更有效地利用水分。（
The net photosynthetic rate,transpiration rate and water content of assimilating sh- oots of Haloxylon ammodendron and H. persicum were measured under different radiation intensities, temperatures changes and different water status. Their water potential under different water status was also measured. The experimental results showed: (1) The dependence of photosynthetic rate and transpiration rate on radiation intensit in the two species of Haloxylon. The increase of net photosynthetic rate and transpiration rate of H. ammodendron depending on radiation intensity was lower than that of H. persicum. Two species of Haloxylon also maintained high transpiration rate under dark. (2) The average transpiration rate of H. persicum was lower than H. ammodendron, showing that H. persicum utilized water more efficiently than H. ammodendron. (3) The o-ptimal temperature of photosynthesis of H. ammodendron was 24-32℃ and the o-ptimal temperature of water utilization of H. ammodendron was 23. 5-25℃. (4) The water potential of H. ammodendron was lower than -3.5 MPa whereas that of H. persicum was lower than -2. 8MPa indicating that the two species of Haloxylon were under severe water stress,and would lead to permanent wilting of their assimilating shoots.
基金
中日阐明沙漠化机制合作研究项目
关键词
梭梭
光合作用
水分
环境
Haloxylon ammodendron
H. persicum
Net photosynthetic rate
Transpiration rate
Transpiration coefficient
