银水牛果和沙棘幼苗在不同土壤水分条件下的光响应研究  

Light Response of Shepherdia Argentea and Hippophae Rhamnoides Seedlings Under Different Soil Moisture Conditions

作　　者：董梅[1] 秦景[1] 贺康宁[1] 张益源[1] 李安超[1] 孙晓涵[1] 郭倩倩[1] 

机构地区：[1]北京林业大学水土保持学院水土保持与荒漠化防治教育部重点实验室,北京100083

出　　处：《水土保持通报》2011年第1期81-86,共6页Bulletin of Soil and Water Conservation

基　　金：国家"十一五"科技支撑项目"黄土高原西部高寒区水土保持型林草植被恢复技术试验示范"(2006BAD03A1203);高等学校博士学科点专项科研基金项目"黄土高原干旱区水土保持林林地土壤干化空间格局及其发生机理研究"(20070022028)

摘　　要：在黄土高寒区,通过人工控制土壤水分的方法,利用Li-6400便携式光合测定系统对银水牛果和沙棘苗木叶片的气体交换参数因子的光响应进行研究。结果表明,2种灌木的净光合速率、蒸腾速率、水分利用效率随着光强的增大而增强,而随着光强进一步增大,净光合速率、水分利用效率却出现下降的趋势,蒸腾速率仍继续增大。随着土壤含水量的增加,2种灌木的净光合速率、蒸腾速率、气孔导度、胞间CO2浓度逐渐增大,水分利用效率先上升,在轻度水分胁迫下达到最大值后下降。在相同土壤含水量下,银水牛果光补偿点明显小于沙棘,光饱和点大于沙棘,光能利用率高于沙棘;银水牛果的表观量子效率大于沙棘,在低光强下的光合能力较高。在水分胁迫下,2种灌木相比,沙棘比银水牛果更易受强光胁迫;银水牛果对弱光的利用能力高于沙棘,水分利用效率高于沙棘,耐旱生产力较高。In the alpine region of Loess Plateau,light responses of S.argentea and H.rhamnoides seedlings under different soil moisture conditions were analyzed in terms of gas exchange parameters using Li-6400 portable photosynthesis system.The results show that net photo-synthesis rate（Pn）,transpiration rate（Tr） and water use efficiency（WUE） of the two species were both increased with PAR in the beginning.With continued increase of PAR,Pn and WUE of S.argentea and H.rhamnoides seedlings declined but Tr still increased.With increasing soil water contents（SWC）,Pn,Tr,Stomatal conductance（Gs） and intercellular CO2 concentration（Ci） of two species were both increased,while WUE increased first and then declined after reaching the maximum under the mild water-stress condition.Under similar soil moisture conditions,light compensation point（LCP） of S.argentea was clearly lower than that of H.rhamnoides,light saturation point（LSP） and efficiency of light energy utilization of S.argentea were higher than those of H.rhamnoides,and the apparent quantum yield（α） in the leaves of S.argentea was higher than that of H.rhamnoides.Compared with H.rhamnoides,S.argentea exhibited higher photosynthetic capacity at low PAR.Contrastive analysis indicates that H.rhamnoides showed stronger response to high PAR under the water-stress condition,while S.argentea had higher utilization capacity of low PAR and WUE.Overall,S.argentea seedlings displayed higher drought-stressed productivity than H.rhamnoides seedlings.

关 键 词：净光合速率 蒸腾速率 水分利用效率 光响应 

分 类 号：S793.9[农业科学—林木遗传育种]