盐胁迫对沙棘幼苗生长与光合生理特征的影响  

Effects of salt stress on growth and photosynthetic physiological features of Hippophae rhamnoides seedlings

作　　者：秦景[1] 董雯怡[2] 贺康宁[1] 陈静[1] 于洋[3] 王占林[4] 

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京林业大学林学院,北京100083 [3]中南林业科技大学资源与环境学院,湖南长沙410004 [4]青海省农林科学院林业研究所,青海西宁810016

出　　处：《生态环境学报》2009年第3期1031-1036,共6页Ecology and Environmental Sciences

基　　金：国家"十一五"科技支撑项目(2006BAD03A1203);高等学校博士学科点专项科研基金项目(20070022028)

摘　　要：用不同浓度的NaCl处理沙棘(Hippophea rhamnoides)2a生幼苗,研究盐胁迫对其生长、叶片水分、光合生理特征以及叶绿素含量的影响。结果表明,随着盐浓度的增加,沙棘幼苗鲜重、干重、比叶重(LMA)和单株总叶面积均明显下降。盐胁迫下,沙棘叶片出现严重的缺水现象,导致叶水势(Ψw)、叶片相对含水量(RWC)逐渐下降,而叶片水分饱和亏缺(WSD)、组织密度(TD)逐渐升高。同时,叶绿素a(Chla)、叶绿素b(Chlb)、总叶绿素(Chl)、类胡萝卜素(Car)含量和叶绿素a/b(Chla/Chlb)与对照相比均极显著降低。随着盐浓度的增加和胁迫时间的延长,沙棘幼苗叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均明显下降,胞间CO2浓度(Ci)先降后升,气孔限制值(Ls)和水分利用效率(WUE)则先升后降。研究表明,Pn下降的原因短期内以气孔限制为主,长期则以叶片生理代谢紊乱、光合色素降解导致的光合能力下降等非气孔限制因素为主,且盐浓度越高,由气孔限制转为非气孔限制的时间越早。With two-year old seedlings of Hippophea rhamnoides as test materials, the growth, water physiological index, photosynthetic physiological features and chlorophyll content in leaves of two-year-seedlings ofHippophea rhamnoides were studied under 0, 200, 400 and 600 mmol·L-1 NaCl solutions. The results showed that with the increase of NaCI concentration, the fresh weight, dry weight, leaf mass per area （LMA） and leaf total area per plant ofH. rhamnoides seedlings declined obviously. Under salt stress, severe water shortage appeared in leaves, the leaf water potential （~w） and relative water content （RWC） decreased gradually, while water saturation deficit （WSD） and tissue density （TD） increased gradually. Compared with the control, the content of chlorophyll a （Chl a）, chlorophyll b （Chl b）, chlorophyll （Chl） and carotenoid （Car） and the chlorophyll a/b （Chl a/Chl b） ratio decreased significantly under salt. When NaC1 concentration increased and stress time prolonged, the net photosynthetic rate （Po）, transpiration rate （Tr） and stomatal conductance （Gs） in leaves of H. rhamnoides seedlings declined markedly, and intercellular CO2 concentration （Ci） declined initially and then increased, whereas, water use efficiency （WUE） and stomatal limiting value （Ls） increased initially and then declined. The results indicated that the decline Of Pn was mainly caused by stomatal limitations in short term, and by non-stomatal limitations in long run, including physiological metabolic disorder of leaves, photosynthetic capacity decline caused by degradation of the photosynthetic pigment, and so on. Moreover, the higher NaCI concentration, the earlier time changing from stomatal limitations into non-stomatal limitations.

关 键 词：盐胁迫 沙棘 生长 水分生理指标 光合生理特征 叶绿素含量 

分 类 号：Q945.78[生物学—植物学]