作 者 ：梁少民1,2，李春发2，张仲伍3，张希明1
期 刊 ：西北植物学报 2013年 6期 页码：1210~1215
关键词：塔克拉玛干沙漠公路；防护林；水分生理；耐旱性；适应特征；
Keywords:Taklimakan Desert Highway, shelterbelt, water physiology, drought tolerance, adaptive characteristics,
摘 要 ：以塔克拉玛干沙漠公路防护林的乔木状沙拐枣(Calligonum arborescens)、多枝柽柳(Tamarix ramosissima)和梭梭(Haloxylon ammodendron)2年生苗木为材料，采用盆栽试验，设置10 d（处理Ⅰ）、20 d（处理Ⅱ）和40 d（处理Ⅲ）的自然干旱胁迫周期，探讨其不同干旱处理下的水分生理特征及其耐旱性。结果表明：（1）3种苗木的水势均随着干旱胁迫程度增强而降低，水势最大降幅均在第2个干旱处理周期内，在第3个干旱处理周期内水势有较大回升，且以乔木状沙拐枣水势最高，梭梭水势最低。（2）乔木状沙拐枣的PV水分参数均随着干旱胁迫强度的增强而降低，其渗透势在第3个干旱周期内开始回升，而初始质壁分离的相对含水量(RWCtlp)一直呈降低趋势，质外体水分含量（AWC）呈现出“降-升-降”的波动状态。乔木状沙拐枣的耐旱能力随着干旱胁迫程度的增强变化不明显，它主要通过减少水分散失适应干旱环境。（3）多枝柽柳的PV水分参数在处理Ⅰ和处理Ⅱ之间差别很小，处理Ⅲ第60天就枯亡；其Ψsat和Ψtlp在第1个干旱周期降低，第2个干旱周期开始回升，而其AWC随胁迫时间在不断增大；多枝柽柳的耐旱能力随着干旱的增强急剧降低，耐旱性最差，它主要通过增加水分散失适应干旱环境。（4）梭梭的Ψsat和Ψtlp在处理Ⅱ、Ⅲ之间非常接近，且都低于处理Ⅰ，RWCtlp与AWC随着干旱强度增强而增大，同期处理Ⅱ和Ⅲ的AWC都高于处理Ⅰ。梭梭的耐旱能力随着干旱的增强不断增强，它通过增加体内水分含量，减少水分散失应对干旱胁迫。（5）3种植物的耐旱能力强弱为：梭梭＞乔木状沙拐枣＞多枝柽柳，所以梭梭最适合做沙漠防护林树种。
Abstract:Water physiology and drought-tolerance of Calligonum arborescens,Tamarix ramosissima and Haloxylon ammodendron under drought stress were studied in Taklimakan Desert Highway shelterbelt.Results are as follows:(1)Water potential of 3 kinds seedling was decreased with the increase of drought stress.The biggest drop of water potential were in the second cycle of drought treatment,while in the third cycle of drought,water potential had a greater recovery.C.arborescens had the highest water potential,Haloxylon the lowest.(2)PV water parameters of C.arborescens were decreased with the increase of drought.The osmotic potential in the third cycle of drought began to rise,and the initial plasmolysis relative water content (RWCtlp) showed a decreasing trend.AWC presented a “down-up-down” fluctuating.Drought tolerance of C.arborescens had little change with drought enhanced,it is mainly by reducing water loss adapt to arid environments.(3)T.ramosissima water parameters of PV are little difference between Ⅰ and Ⅱ,but plants withered in the first 60 days treatment Ⅲ.There is little difference in PV water parameters of T.ramosissima between Ⅰ and Ⅱ,treatment Ⅲ first 60 day on dry death.Its Ψsat and Ψtlp reduced in the first period of drought,recovered in the second period,but its apoplastic water content (AWC) was constantly increasing.Drought tolerance of T.ramosissima reduced drastically with enhanced drought,so it is the worst to drought tolerance.It is mainly adapted to arid environments through increased water loss.(4)Ψsat and Ψtlp of Haloxylon were close between Ⅱ and Ⅲ and were lower than Ⅰ.RWCtlp and AWC were increased with the enhanced of drought.AWC of Haloxylon of Ⅱ and Ⅲ were higher than Ⅰduring the same period.Drought tolerance of Haloxylon was enhanced with drought been exacerbated.It coped with drought stress by increasing body water content and reducing water loss.(5)Drought tolerance of three plants is:Haloxylon>C.arborescens>T.ramosissima,so the most suitable desert shelterbelt species is Haloxylon.