摘要
以盆栽湿地松幼苗为材料,通过实验室模拟三峡库区从水淹到干旱的过程,设置常规供水(CK)、常规供水-轻度干旱-复水(DR),水淹(FL),水淹-轻度干旱-复水(FD)4个实验组,研究土壤水分交替变化对湿地松幼苗光合参数及叶绿素含量的影响.结果表明:(1)不同土壤水分处理条件对湿地松幼苗的净光合速率、气孔导度、蒸腾速率、胞间CO2浓度、气孔限制值、水分利用效率和光合色素含量都有一定影响.(2)在实验的前中期,DR、FL和FD组湿地松幼苗的光合速率、气孔导度、蒸腾速率都显著下降,DR和FD在实验后期回升到较高水平.(3)在整个实验期间各处理组的水分利用效率较对照都有不同程度上升,并以DR组的最大(4.95μmol·mmol-1).(4)随着处理时间延长,各处理组湿地松幼苗的总叶绿素含量及叶绿素a/b值均呈先降后升的趋势,其中叶绿素/类胡萝卜素的比值在4.379～6.019间波动,而叶绿素a/b值则在2.207～2.850间波动.研究发现,湿地松幼苗在水分代谢、光合生理等方面等能够很好地适应水淹以及"淹-干"的水分交替变化环境,并且在解除胁迫后能够迅速恢复生长,可以考虑用于三峡库区消落带的植被修复和重建.
To research the impacts of soil water alternative variation on photosynthetic characteristics of Pi- nus elliottii seedlings, four different kinds of water treatment simulating processes in the Three Gorges Reservoir Area from flooding to drought were applied,including regular water supply （CK） ,regular water supply-mild drought-rehydration （DR）, flooding （FL）, flooding-mild drought-rehydration （FD）. Results showed that ： （1） Water treatment could significantly influence net photosynthetic rate, stomatal conduct- ance, transpiration rate, intercellular carbon dioxide concentration, water use efficiency and photosynthetic pigment content of P. elliottii seedlings （P〈0.05）. （2）In the earlier and middle stage of experimental pe- riod, photosynthetic rate, stomatal conductance and transpiration rate showed significant decline in DR, FL and FD compared with CK,whereas those in DR and FD came back to a high level later. （3）Every treat- ment showed increase in water use efficiency with contrast to CK to different extents in the whole experi- mental period,with the maximum of 4.95 μmol · mmo1-1 in DR. （4）Along with the extended period of time, an increase followed by decline tendency was displayed in contents of total chlorophyll, chlorophyll/carotenoid and chlorophyll a/b in four treatments. Chlorophyll/carotenoid ranged from 4. 379 to 6. 019 while that of chlorophyll a/b was 2. 207 to 2. 850. These results indicated that P. elliottii seedling has a competitive adaptation to flooding and ＂flooding-drought＂ alternative variation in terms of growth, water metabolism and photosynthetic physiology. Additionally, it could recover growth condition rapidly after stress release. Therefore,P. elliottii could be a candidate species for revegetation of riparian in the Three Gorges Reservoir Area.
出处
《西北植物学报》
CAS
CSCD
北大核心
2012年第5期980-987,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家林业公益性行业科研专项(201004039)
国家教育部“留学回国人员科研启动金”(教外司留[2010]1561号)
中央高校基本科研业务费专项资金重点项目(XDJK2009B032)
关键词
土壤水分
交替变化
湿地松幼苗
光合特性
光合色素
soil moisture
alternative variations
slash pine seedlings
photosynthetic characteristics
photo- synthetic pigments
