【摘要】 采用盆栽试验方法,于5月份高生长速生期研究了连续水分梯度变化过程中几个黑杨派杂交无性系的叶片水势、净光合速率、蒸腾速率以及其水分利用效率。研究结果表明:随控水时间的加长,叶片水势(每天的平均值)呈递减趋势,A69、B33、B34叶片水势下降趋势小于对照I-107,而A50、陈1、B40、B53叶片水势下降趋势则大于对照I-107。土壤水分连续下降过程中各无性系叶片光合速率明显下降,其中B34、A50光合速率下降缓慢,A69、B53、B40光合速率下降迅速,而陈1、B33、I-107光合速率下降幅度介于上述两组无性系之间。各无性系叶片蒸腾速率在土壤水分连续下降过程中大幅度下降,无性系之间叶片蒸腾速率差异显著,叶片蒸腾速率与土壤水分呈显著负相关,杨树无性系的水分利用效率与叶片水势不相关,但是与土壤水势存在一定的相关性。说明这几个杨树无性系的水分利用效率主要受土壤水分条件的影响。更多还原

【Abstract】 Through potted experimentation,leaf water potential,photosynthesis rate,transpiration rate and water use efficiency of potted seedlings of crossbreed Aigeiros clones under continuous soil moisture gradient changes were measured and analyzed in the fast growing period of May.The results showed that: prolonged water stress caused decline of leaf water potential;the docreasing trend of leaf water potential of A69、B33、B34 was smaller than that of CK I-107,but A50,Chen1,B40 and B53 was larger than that of CK I-107.The photosynthesis rate of all the clones under drought stress declined remarkably,the photosynthesis rate of B34 and A50 declined tardily,and that of A69,B53 and B40 declined rapidly,that of the other clones was between the above-mentioned two groups.The transpiration rate of all the clones declined greatly with soil moisture decline.The transpiration rate of every clone differed significantly.The leaf transpiration rate had a significantnegative relationship with soil moisture,and the water use efficiency had a significant relationship with soil water potential,but had no significant relationship with the leaf water potential.This indicated that the soil moisture mostly influenced the water use efficiency of these crossbreed Aigeiros clones.更多还原