5种沙地灌木对干旱胁迫的生理生态响应  

Ecophysiological Responses of Five Sandy Shrubs to Drought Stress

作　　者：罗青红[1,2] 宁虎森[1] 何苗 吉小敏[1] 雷春英[1] Luo Qinghong;Ning Husen;He Miao;Ji Xiaomin;Lei Chunying(Afforestation and Sand Control Institute of Xinjiang Academy of Forestry Urumqi 830063;Xinfiang Institute of Ecology and Geography, Chinese Academy of Sciences Urumqi 830011)

机构地区：[1]新疆林业科学院造林治沙研究所,乌鲁木齐830063 [2]中国科学院新疆生态与地理研究所,乌鲁木齐830011

出　　处：《林业科学》2017年第11期29-42,共14页Scientia Silvae Sinicae

基　　金："十二五"国家科技支撑计划项目(2012BAD16B03)

摘　　要：【目的】探讨沙地灌木对干旱胁迫的动态生理生态适应性及抗旱能力,为沙区选种育种以加快植被恢复提供理论支持。【方法】以柠条、沙地桑(鲁桑×蒙桑)、沙木蓼、红皮沙拐枣和北沙柳为研究对象,设置4个控水梯度[T1(CK,12 000 m3·hm^(-2))、T2(9 600 m3·hm^(-2))、T3(7 200 m3·hm^(-2))和T4(4 800 m3·hm^(-2))]和3个控水时期:控水前期(7月)、控水中期(8月)和控水后期(9月),定期测定供试植物的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、茎水势、叶绿素、脯氨酸(Pro)含量、可溶性糖含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性及可溶性蛋白含量。【结果】1)除控水中期的沙木蓼和控水后期北沙柳的叶绿素相对含量外,各树种的光合指标和水势均随干旱程度的加剧逐渐下降;2)Pn随控水时间逐渐降低,Ci表现为逐渐升高;柠条、沙地桑和沙木蓼的Tr及Gs在控水前期至控水中期升高,控水后期又显著降低,其余树种呈逐渐降低的趋势;各树种水势在控水前期处于-0.093^-0.23 MPa,在控水中后期分别下降了1.44 MPa和1.22 MPa;红皮沙拐枣的叶绿素含量显著低于其他树种,北沙柳的叶绿素相对含量在中后期仅为前期的47%;3)控水后期,各树种的SOD和POD活性差异较大,最大值分别为最小值的10倍和323倍。在轻度干旱胁迫下,各树种的Pro含量、可溶性糖含量、SOD活性、POD活性及可溶性蛋白积累量快速升高,而随胁迫程度的加剧(中度和重度),其积累量又逐渐降低;胁迫程度由轻度到重度,除沙地桑的MDA含量逐渐降低外,其余物种的MDA含量均逐渐上升,其中红皮沙拐枣的MDA含量增幅最大,比对照上升了3.47倍;4)Pro含量、可溶性糖含量以及Ci与第1主成分呈极强的相关性,各树种的主成分得分大小顺序为:柠条>沙木蓼>沙地桑>红皮沙拐枣>北沙柳,各树种T4水平因子得分均为负值。【结论】在干旱【Objective】Desertification is one of the important ecological and environmental problem in Xinjiang,and habitat drought is a major limiting factor for vegetation growth in this region. Thus,understanding physiological and ecological adaptability and drought tolerant of sandy shrub is of great significance for selective breeding and vegetation restoration in desert area.【Method】Five sandy shrubs,i. e. Caragana korshinskii,Morus alba var. multicaulis × M.mongolica,Atraphaxis bracteata,Calligonum rubicundunm,Salix psammophila,were subjected to four water gradients of T1（ CK,12 000 m3·hm^-2）,T2（ 9 600 m3·hm^-2）,T3（ 7 200 m3·hm^-2）,and T4（ 4800 m3·hm^-2） in growth season. The duration of water treatment were divided into three stages of early stage（ July）,medium stage（ August） and late stage（ September）. The ecophysiological indexes of net photosynthetic rate（ Pn）,transpiration rate（ Tr）,stomatal conductance（ Gs）,intercellular CO2 concentration（ Ci）,water potential,chlorophyll,the proline（ Pro） content,soluble sugar content,superoxide dismutase（ SOD） activity,peroxidase（ POD） activity and soluble protein content were measured. 【Result 】1） The photosynthetic indexes and water potential of sandy shrubs decreased with the stressintensifying,except for chlorophyll contents of C. korshinskii at medium stage and S. psammophila at late stage of treatments. 2） The Pnof five shrubs gradually decreased and Ciwas increased with stress intensifying. The Tr and Gsof A. bracteata,M. alba and S. psammophila increased from early to medium stage of treatment,and significantly decreased at late stage. The water potential of all shrubs at early treatment stage was from-0. 93 to-2. 34 MPa,and further reduced by 14. 38 MPa and 12. 22 MPa at the medium and late stage. The chlorophyll content of C. rubicundum was significantly lower than others. The SPAD of S. psammophila in medium and late stage was 47% of that at early stage.3） At the late treatment stage,the a

关 键 词：沙地灌木 干旱胁迫 抗旱性 生理指标 综合评价 

分 类 号：S718.43[农业科学—林学]