胡杨(Populus euphratica)对干旱胁迫的生态适应

Ecological adaptation of Populus euphratica to drought stress

以两年生胡杨幼苗为试材,采用盆栽实验,比较胡杨(Populus euphratica)在干旱胁迫下的生态适应性。结果表明:在植物整体方面,随着干旱程度的增加,胡杨枝条和叶片的导水能力均增加,通过增加导水率形成了在干旱环境下对水分的有效吸收和传输。同时,胡杨在干旱胁迫下增加水力利用效率\,维持体内的水分利用能力。在细胞层面,胡杨通过积累生物酶和脯氨酸维持渗透平衡,其中脯氨酸起到持续性的保护作用。胡杨通过叶片厚度及栅栏组织厚度的增加形成了对干旱具有适应性的储水和保水结构,达到了对水分的有效保持。在干旱胁迫时,胡杨从微观到宏观进行了一系列的调整,形成了对水分的有效吸收及传输、保持和利用的适应体系。对胡杨干旱适应性的研究对黑河下游生态系统的恢复和重建具有重要意义。

Pot experiment was designed to compare the ecological adaptability of Populus euphratica under different drought stress by using two-year old seedlings.The results showed:as for the whole plant,with the increase of drought stress,the water conductance of whole shoots and leaves increased,and P.euphratica could absorb and transmit water effectively in arid environment by increasing the hydraulic conductance.At the same time,P.euphratica could maintain water use ability by increasing water use efficiency under drought stress.At the cellular level,P.euphratica maintained osmotic adjustment by accumulating biological enzymes and proline,and the effect of proline provided continuous protection.P.euphratica formed an adaptive water storage and water retention structure with the increase of leaf thickness and palisade tissue thickness.As a result,the effective maintenance of water was formed.In the face of drought stress,P.euphratica made a series of adjustments from micro to macro to form an adaptive system,which was effective in absorption and transmission,maintenance and utilization of water.The study of drought adaptability in P.euphratica is vitial to the restoration and reconstruction of ecosystem in the lower reaches of the Heihe River.