水分胁迫对白杨杂种无性系生理和生长的影响

PHYSIOLOGY AND GROWTH OF HYBRID CLONE OF WHITE POPLAR IN RESPONSE TO WATER STRESS

为探索水分胁迫对白杨杂种无性系气体交换和生长的影响，以白杨双杂交杂种新无性系Ｂ４３０苗木为试验材料，在３种水分胁迫条件下，对各无性系生理和生长指标进行了分析。结果表明，在不同水分胁迫下，无性系苗木的Ｐｎ、Ｔｒ、Ｇｓ、Ｌａ、Ｃｉ等日变化模式基本一致，但受胁迫的苗木各生理过程受到明显抑制。各生长指标对水分胁迫的敏感性不同，苗高和单叶叶面积对水分胁迫最敏感，叶片数和生物量的敏感性较差，随着水分胁迫加强，茎／根值迅速提高。

With the one year old seedlings of the double cross hybrid clone of white poplar B430 as the experimental materials, the major physiological properties of the clone were measured under condition of three artificial controlled drought gradients. The result showed that under the different conditions of soil drought stress, the daily variation patterns of Pn, Tr, Gs, La and Ci were identical, but the physiological activity of the seedlings stressed was restrained obviously. The sensitivity of the growth indices to water deficit was different from each other. Seedling height and single leaf area were the most sensitive to water stress, and the sensitivity of the leaf quantity and biomass was lower. The ratio of stem and leaf biomass to root biomass decreased with the water stress developing.