| 摘要: |
| 【目的】研究土壤干旱胁迫对槭叶草生长及光合生理特性的影响，为槭叶草的引种驯化及在园林绿化中的应用提供理论依据。【方法】以长白山槭叶草3年生种子苗为试验材料，采用盆栽控水方式，以正常浇水为对照，研究干旱胁迫0 (胁迫前)，5，10，15，20，25和30 d槭叶草的生长、生理指标、光合色素含量及光合参数的变化。【结果】随着干旱胁迫时间的延长，槭叶草的株高和叶面积呈先升高后降低的趋势，叶片相对含水量、叶绿素及类胡萝卜素含量显著下降，叶片自然水分饱和亏缺、相对电导率(REC)及丙二醛(MDA)含量均不断升高。叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)均不断下降，胞间CO2浓度(Ci)先降低后升高，水分利用率(WUE)和气孔限制值(Ls)先升高后降低。干旱胁迫15 d以内(盆栽基质的相对含水量(SRWC)为18.49%)，槭叶草叶片净光合速率下降是由气孔限制因素引起的；而此后，随着干旱时间的延长，净光合速率的下降是由非气孔限制因素引起的。【结论】槭叶草表现出较强的抗旱性；在发生持续干旱时，对槭叶草进行补水最好能在干旱发生的15 d内进行。 |
| 关键词: 干旱胁迫 槭叶草 生理指标 光合参数 |
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| 基金项目:吉林省科技厅科技支撑计划项目（20100259） |
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| Effect of drought stress on growth and photosynthetic physiological characteristics of Mukdenia rossii |
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ZHANG Shuang,DONG Ran,DONG Yan,et al
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| Abstract: |
| 【Objective】The effect of drought stress on growth and photosynthetic physiological characteristics of Mukdenia rossii was studied to provide theoretical basis for the introduction,domestication and application in landscaping.【Method】Using pot experiments,the changes in growth,physiological indexes,photosynthetic pigment content and photosynthetic parameters of triennial seedlings of M.rossii were investigated under the drought stresses of 0(before stress),5,10,15,20,25,and 30 d in comparison with regular watering seedlings.【Result】With the prolonging of drought stress,the plant height and leaf area decreased after initial increase,relative water content of leaf and contents ofchlorophyll (Chl.) and carotenoid (Car.) decreased significantly,and water shortage under natural saturation,relative electric conductivity (REC) as well as the content of malondialdehyde (MDA) increased gradually.The net photosynthetic rate (Pn),stomatal conductance (Gs),and transpiration rate (Tr) decreased,the intercellular CO2 concentration (Ci) increased after initial decrease,and the water use efficiency (WUE) and stomatal limitation value (Ls) decreased after initial increase.The decrease of Pn after 15 d drought stress was due to stomatal factors (SRWC was 18.49%),but the reason changed when the drought stress was longer than 15 d.【Conclusion】M.rossii has good drought tolerance and it is better to water M.rossii within the first 15 d of drought. |
| Key words: drought stress Mukdenia rossii physiological indexes photosynthetic parameters |
