干旱胁迫对两种沙地灌木能源树种光合特性的影响  

Effect of drought stress on photosynthetic characteristics of two energy resource sandy shrubs

作　　者：孙龙[1] 彭祚登[1] 王冲[1] 杨腾[1] 

机构地区：[1]北京林业大学、省部共建森林培育与保护教育部重点实验室,北京 100083

出　　处：《南京林业大学学报（自然科学版）》2014年第2期99-104,共6页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：教育部博士点基金优先发展领域课题(2012001413001)

摘　　要：为了研究干旱胁迫对两种灌木能源树种光合特性的影响,选择沙枣(Elaeagnus angustifolia L.)1年生实生苗和多花柽柳(Tamarix hohenackeri Bunge)1年生扦插苗为试验材料,通过4个不同土壤水分条件下的盆栽试验,测定叶片叶绿素含量和光合参数。结果表明:多花柽柳在各个土壤水分条件下叶片叶绿素含量均低于沙枣,多花柽柳在中度干旱胁迫条件下叶绿素含量增加,沙枣在重度干旱胁迫条件下叶绿素仍然有较高含量。随着干旱胁迫程度加重,2个树种净光合速率、蒸腾速率和气孔导度均呈下降的趋势,在中度干旱条件下净光合速率和蒸腾速率下降更明显,但胞间CO2浓度呈上升趋势。多花柽柳净光合速率和蒸腾速率日变化均呈现出"双峰"曲线,11:00时出现"光合午休"现象,气孔导度呈现"单峰"曲线;沙枣净光合速率日变化呈"单峰"曲线,上午明显高于下午。两树种蒸腾速率日变化和气孔导度日变化均表现为"双峰"曲线,呈现正相关性。In order to study the effects of drought stress on photosynthetic characteristics of two energy resource shrubs, one-year-old Elaeagnus angustifolia L. seedlings and Tamarix hohenackeri Bunge cutting seedlings were selected as the experimental materials. Their leaf chlorophyll content and photosynthetic parameters under four different soil water condi-tions were measured in the water-controlling pot experiments. The results showed that the leaf chlorophyll content of T. hohenackeri was lower than E. angustifolia at various soil moisture conditions, leaf chlorophyll content of T. hohenackeri increased under moderate drought stress and there was still a higher content of E. angustifolia in severe drought stress conditions. With the aggravation of drought stress, the net photosynthesis rate （ Pn） , transpiration rate （ Tr） and stoma-tal conductance （ Gs） of both two tree species showed a tendency of decrease, and under moderate drought stress, Pn and Tr decreased more significantly, while the intercellular CO2 concentration （ Ci） increased. The diurnal variation curves of both Pn and Tr of T. hohenackeri displayed the two-peak pattern with a typical midday depression at 11：00 un-der different levels of drought stress, while Gs presented a single-peak curve. The diurnal variation of Pn of E. angustifo-lia displayed a single-peak curve, which was significantly higher in the morning than in the afternoon. Tr and Gs of two shrubs were displayed in two-peak pattern and positively correlated.

关 键 词：干旱胁迫 光合特性 日变化 多花柽柳 沙枣 

分 类 号：S718[农业科学—林学]