干旱胁迫对5个种源沙柳(Salix psammophila)气体交换及水分利用效率的影响  

Influence of Drought Stress on Gas Exchange and Water Use Efficiency of Salix psammophila Growing in Five Places

作　　者：刘海燕[1] 李吉跃[1] 赵燕[1] 黄看看[1] 

机构地区：[1]北京林业大学资源与环境学院北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083

出　　处：《干旱区研究》2007年第6期815-820,共6页Arid Zone Research

基　　金：国家自然科学基金项目(30070637);北京市科委项目"北京城市园林绿化耐旱;节水园林植物筛选和应用研究";森林培育与保护实验室"北京城市绿地水分经济生态"(JD100220535)课题资助

摘　　要：在盆栽条件下,对5个种源沙柳进行了水分胁迫处理,在不同干旱阶段对苗木叶水势、土壤含水率、蒸腾速率、光合速率等气体交换特性及水分利用效率进行了研究。结果表明:沙柳属于亚低水势忍耐脱水耐旱树种,叶水势随土壤含水量的下降而下降,变化趋势可用双曲线方程y=a+b/x(0.389 0<a<0.520 3,8.9066<b<11.4669)拟合,其中民勤种源沙柳的双曲线方程中b值最低,为8.91,表现出较强的耐旱特性。在正常水分供应条件下,榆林种源沙柳的光合速率为23.89μmol/(m2.s),水分利用效率为3.44μmol/mmol,表现出很强的光合生产能力。随着干旱胁迫的加剧,各种源沙柳苗木的水分利用效率均有不同程度增加,民勤种源沙柳的增加值最大,为0.75μmol/mmol,表现出了较强的抵抗干旱的能力,而榆林种源沙柳对水分亏缺则非常敏感,光合速率、蒸腾速率都急剧下降。这充分表明在水分供应充足的条件下,榆林种源沙柳具有最大的光合生产潜力;而当遇到干旱胁迫时,民勤种源沙柳则表现出极强的维持体内水分平衡的能力,是5个种源中最耐旱的种源。In this study, the values of gas exchange of Salix psammophila growing five places （ such as leaf water potential, transpiration, net photosynthetic and water use efficiency of Salix psammophila） and soil moisture content are measured, and the drought stresses on the growth of potted Salix psammophila seedlings is studied. The resuits show that Salix psammophila is a plant species with low water potential and high dehydration tolerance and drought tolerance, its leaf water potential is decreased with decreasing soil moisture content and can be fitted with the equation of y = a ＋ b/x （0. 389 0 〈 α 〈 0. 520 3, 8.906 6 〈 b 〈 11. 466 9）. In the hyperbolic equation, the b value of Salix psammophila growing in Minqin County, 8.91, is the lowest, which reveals that the drought tolerance of Salix psammophila growing in Minqin is high. When water supply is sufficient, the net photosynthetic of Salix psammophila growing in Yulin is 23.89 μmol/（ m^2 ·s）, and the water use efficiency is 3.44 μmol/mmol, which reveals that the photosynthesis production of Salix psammophila growing in Yulin is high. The water use efficiency of Salix psammophila growing in five places is increased with increasing drought stress, in which that in Minqin is the highest and for 0.75 μmol/mmol, which also reveals that the drought tolerance ofSalix psammophila growing in Minqin is high, while Salix psammophila growing in Yulin is extremely sensitive to drought stress, and its transpiration and net photosynthetic rate are sharply decreased. These reveal that the photosynthesis production of Salix psammophila growing in Yulin is the highest under sufficient water supply, and the drought tolerance of Salix psammophila growing in Minqin is the highest under drought stress.

关 键 词：沙柳 干旱胁迫 气体交换 水分利用效率 内蒙古 

分 类 号：S793.9[农业科学—林木遗传育种]