乌鲁木齐周边3种野生灌木对干旱胁迫的响应

Responses of Three Native Shrubs to Drought Stress in Urumqi

木本猪毛菜(Salsola arbucula)、刺旋花(Convolvulos tragacanthoides)和刺木蓼(Atraphaxis spinosa)为乌鲁木齐周边植被组成的重要种,在维持荒漠生态系统的稳定中发挥着重要作用,是植被恢复过程中潜在的候选植物种。该文以盆栽控水法,分析比较了3种野生灌木在不同干旱胁迫下的生理生长特征的差异。结果表明,干旱胁迫下3种灌木均表现出良好的耐旱能力。在生长方面,刺旋花生长受到的影响最小,重度胁迫下其生物量与适宜水分处理相比仅减少9.7%,根系极发达,根冠比大。木本猪毛菜受抑制严重,重度干旱时株高和基茎增量为适宜水分处理的17.85%和21.63%。生理方面,刺旋花叶片叶绿素含量最高,膜系统受破坏较小,渗透调节可以通过可溶性糖的积累来实现。木本猪毛菜膜系统受破坏较小,脯氨酸的积累对渗透调节起重要作用。刺木蓼的脯氨酸和可溶性糖两种渗透调节物质均起重要作用。总之,木本猪毛菜和刺木蓼在轻度干旱下表现良好,刺旋花则能够在重度干旱下保持植物体正常的生理代谢功能,表现出对干旱环境较强的适应能力。

Salsola arbucula,Convolvulos tragacanthoides and Atraphaxis spinosa are important components of the vegetation in Urumqi.They play an important role in maintaining ecosystem stability in the area.The responses to drought stress on growth and physiological characteristics of these shrubs were studied in this paper.The results showed that the height,basal diameter and the biomass of these shrubs were differently decreased at the three levels of water stress.The distribution of biomass was also affected by drought stress.The growth of C.tragacanthoides hardly decreased with the water stress.With the drought stress,the contents of malondialdehyde（MDA）,proline and soluble sugar increased at different levels.The content of chlorophyll decreased.In conclusion,S.arbucula and A.spinosa grew well under the mild water stress.C.tragacanthoides grew better under moderate and severe water stress.