石漠化地区3个树种幼苗在水分胁迫下的光合特性与抗旱性关系  

Relations between Seedlings' Photosynthetic Characteristics and Their Drought Tolerance under Water Stress in Rocky Desertification Area

作　　者：徐利霞[1] 杨水平[1] 姚小华[2] 李生[2] 任华东[2] 

机构地区：[1]西南大学资源环境学院,重庆400716 [2]中国林业科学研究院亚热带林业研究所国家林业局亚热带林木培育重点开放性实验室,浙江富阳311400

出　　处：《林业科学研究》2006年第6期785-790,共6页Forest Research

基　　金：国家林业局重点项目"石漠化地区植被恢复与生态重建技术试验示范"(2003-053-L53);国家林业重点工程科技支撑项目"喀斯特石漠化地区植被恢复与重建技术研究"的部分内容

摘　　要：采用盆栽控水方法,研究了翅莢木、滇楸和银荆树3树种当年生实生苗的光合特性与抗旱性的关系。结果表明:随着干旱胁迫强度的增加和时间的延长,3树种的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)均呈下降趋势,而胞间CO2浓度则呈上升的趋势;净光合速率日变化曲线逐渐从典型的单峰型转变成双峰型,出现“光合午休”现象。在轻度胁迫和中度胁迫下,净光合速率的降低是由气孔因素和非气孔因素共同引起的:而重度胁迫下,净光合速率的降低主要是非气孔因素引起的。干旱复水后,3个树种的净光合速率均有明显的恢复。利用隶属函数与反隶属函数法对3个树种的抗旱能力进行综合评价,其抗旱能力为:银荆树>翅莢木>滇楸。Water-controlling pot experiments were carried out on characteristics of photosynthesis and drought tolerance under water stress of 3 tree species ： Zenia insignis, Catalpa fargesii f. duclouxii and Acacia dealbata from a rocky desertification area in Guizhou Province. The results were as follows：As stress increasing and time delaying, the net photosynthesis rate（Pn）, transpiration, stomata conduct were gradually decreased but CO2 concentration in stomata was increased ;the diurnal pattern of net photosynthetic rate shifted gradually from a typical single-peaked curve to a double-peaked one that signified midday depression of photosynthesis. The midday depression of photosynthesis under both light and heavier stress may be induced by a combination of stomatal limitation and non-stomatal factors,but under extreme drought conditions, induced mainly by the non-stomatal factors. The depressed Pn could recover when rehydrated under certain drought stress. By a comprehensive evaluation of Fuzzy mathematics, the ability of drought tolerance was arranged from strong to weak as following：Acacia dealbata 〉 Zenia insignis 〉 Catalpa fargesii f. duclouxii.

关 键 词：石漠化地区造林树种 光合特性 抗旱性 

分 类 号：Q945.11[生物学—植物学]