林业科学2017，Vol.53Issue(11)：29-42,14.DOI:10.11707/j.1001-7488.20171104
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
摘要
Abstract
[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,12000 m3·hm -2),T2 (9600 m3·hm -2),T3 (7200 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 stress intensifying,except for chlorophyll contents of C. korshinskii at medium stage and S. psammophila at late stage of treatments. 2) The Pn of five shrubs gradually decreased and Ci was increased with stress intensifying. The Tr and Gs of 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 activities of SOD and POD of each species varied greatly,and the maximum values were 10 times and 323 times higher than that of the minimum value,respectively. The Pro,soluble sugar and soluble protein content,SOD and POD activity of five shrubs increased gradually under mild drought stress,and they began to gradually decline with the stress intensifying. The MDA of M. alba var. multicaulis × M. mongolica decreased gradually but that of other shrubs increased with the increase of drought degree,especially for C. rubicundum,its MDA content under severe stress was 3. 47 times higher than that of CK (T1). 4) The Pro content,soluble sugar content,and Ci of shrubs showed a very strong correlation with the first principal component. The score order of principal component was A. bracteata > C. korshinskii > M. alba var. multicaulis × M. mongolica > C. rubicundum > S. psammophila. All species had the negative factors score under severe drought stress (T4).[Conclusion]Under drought stress,each species improved their adaptability through accumulating more osmotic adjustment substances and improving antioxidant enzyme activity,but severe stress reduced their photosynthesis,transpiration and other physiological activities. A. bracteata,C. korshinskii,and M. alba var. multicaulis × M. mongolica have better drought resistance than C. rubicundum and S. psammophila. The content of Pro,soluble sugar content and Ci can well indicate the drought resistance ability of the five sandy shrubs.关键词
沙地灌木/干旱胁迫/抗旱性/生理指标/综合评价Key words
sandy shrub/drought stress/drought resistance/physiological index/comprehensive evaluation分类
农业科技引用本文复制引用
罗青红,宁虎森,何苗,吉小敏,雷春英..5种沙地灌木对干旱胁迫的生理生态响应[J].林业科学,2017,53(11):29-42,14.基金项目
"十二五"国家科技支撑计划项目(2012BAD16B03). （2012BAD16B03）
