水分胁迫对银中杨耗水特征与水分利用的影响

Characteristics of water consumption and utilization of Populus alba×berolinensis under water stress

在不同供水条件下,采用LI-6400光合作用系统(LI-COR,1995,USA)和电子天平等仪器,对银中杨苗木气体交换、蒸腾耗水量和水分利用效率及其有关环境因子进行了测定。结果表明,在研究的诸环境因子中,土壤含水量是制约苗木蒸腾耗水的主导因子;苗木的蒸腾耗水量随土壤干旱胁迫的加重而减少,并且当土壤含水量低于田间持水量的50%时,气象因子对苗木蒸腾耗水的影响不再明显;土壤含水量为田间持水量的70%时,银中杨苗木的净光合速率和蒸腾速率下降不显著,而水分利用效率有所提高,为2.579μmol.mmol-1,在土壤含水量大于田间持水量的70%的水分条件下,银中杨苗木可以正常生长。

Employing LI-6400 photosynthesis system （LI-COR, 1995, USA）, this paper studied the gas exchange, water consumption, and water use efficiency of Populus alba × berolinensis seedlings under different water supply, The results showed that among test environmental factors, soil moisture content was the dominant one affecting seedlings transpiration. The water consumption of the seedlings decreased with increasing drought stress, but the effects of meteorological factors were not obvious when soll moisture content was lower than 50 % of field capacity. P. alba × berolinensis seedlings could grow well when soil moisture content was higher than 70% of field capacity.