| 黄河三角洲贝壳砂干旱生境杠柳(Periploca sepium)叶片的光合作用特征 |
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| 引用本文： | 王晓,夏江宝,周东兴,赵自国,董林水.黄河三角洲贝壳砂干旱生境杠柳(Periploca sepium)叶片的光合作用特征[J].中国沙漠,2019(4):139-148. |
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| 作者姓名： | 王晓 夏江宝 周东兴 赵自国 董林水 |
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| 作者单位： | 东北农业大学资源与环境学院;滨州学院山东省黄河三角洲生态环境重点实验室 |
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| 基金项目： | 国家自然科学基金项目(31770761);山东省重点研发计划项目(2017GSF17104);山东省林业科技创新项目(LYCX07-2018-38);山东省高等学校科技计划项目(J16LH53) |
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| 摘 要： | 水分是黄河三角洲贝壳堤滩脊地带植被生长的主要限制因子。以4年生杠柳(Periploca sepium)苗木为对象,模拟贝壳砂干旱生境,设定对照(土壤相对含水量RWC为77.72%)、轻度(RWC为58.16%)、中度(RWC为42.98%)及重度(RWC为32.39%)干旱胁迫4组水分梯度,测定分析杠柳叶片气体交换参数的光响应以及叶绿素荧光参数。结果表明:(1)水分条件可显著影响贝壳砂生境杠柳叶片的光合效率。随干旱胁迫的加重,杠柳净光合速率(Pn)显著下降,重度干旱胁迫下,Pn最小,为0.62μmol·m^-2·s^-1,仅是对照的5%。表观量子效率、光饱和点和暗呼吸速率随干旱胁迫的加重逐渐降低,而光补偿点逐渐升高。干旱胁迫导致杠柳叶片光照生态幅变窄,光能利用率降低。(2)随干旱胁迫加重,杠柳蒸腾速率显著下降。适度干旱胁迫可显著提高杠柳的水分利用效率,在轻度、中度干旱胁迫下维持较高值,而对照和重度干旱胁迫下显著降低。在轻度、中度干旱胁迫下,杠柳Pn下降主要受气孔限制,而重度干旱胁迫则以非气孔限制为主。(3)随干旱胁迫加重,杠柳叶片潜在光化学效率、实际光化学效率和非循环光合电子传递速率均显著下降,受到光抑制,电子传递效率下降;非光化学猝灭系数显著增加,光能热耗散增多。杠柳叶片通过调节光合效能来适应干旱胁迫逆境,对干旱逆境表现出一定的可塑性和适应性。
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| 关 键 词： | 杠柳(Periploca sepium) 贝壳砂 干旱胁迫 气体交换参数 叶绿素荧光 |
Photosynthesis Characteristics of Periploca sepium under Drought Stress in Shell-sand Habitat in the Yellow River Delta |
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| Wang Xiao,Xia Jiangbao,Zhou Dongxing,Zhao Ziguo,Dong Linshui.Photosynthesis Characteristics of Periploca sepium under Drought Stress in Shell-sand Habitat in the Yellow River Delta[J].Journal of Desert Research,2019(4):139-148. |
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| Authors: | Wang Xiao Xia Jiangbao Zhou Dongxing Zhao Ziguo Dong Linshui |
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| Institution: | (College of Resources and Environment,Northeast Agricultural University,Harbin 150030,China;Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta,Binzhou University,Binzhou 256603,Shandong,China) |
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| Abstract: | Water is the main limiting factor of vegetation growth in the Ridge of Shell Beach in the Yellow River Delta.Four year old Periploca sepium were used as experimental materials.Four soil water content levels,including control(soil relative water content,RWC=77.72%),mild(RWC=58.16%),moderate(RWC=42.98%)and severe drought stress(RWC=32.39%)groups,were set up to simulate drought stress in sand habitat formed from seashells.The light response of the leaf gas exchange parameters and chlorophyll fluorescence parameters under different water conditions were measured and analyzed.The results showed as follows.(1)Water conditions could influence the photosynthetic efficiency of leaves in shell beach ridge significantly.With the increase of drought stress,the net photosynthetic rate(Pn)decreased significantly.Under severe drought stress,the minimum of Pn was 0.62μmol·m^-2·s^-1,which was only 5%of the control.The apparent quantum yield,light saturation point and dark respiration rate decreased with the increase of drought stress,but the light compensation point increased gradually.Narrower ecological amplitude of light and lower utilization rate of light energy arose as results of drought stress.(2)With the increase of drought stress,the transpiration rate decreased significantly.The water use efficiency(WUE)increased significantly under appropriate drought stress.WUE were much higher under mild and moderate drought stress compared with control and severe drought stress.Under mild and moderate drought stress,the decrease of Pn was mainly restricted by stomata,while the non-stomatal limitation was dominant under severe drought stress.(3)With the increase of drought stress,the maximum photochemical efficiency,the actual photochemical efficiency and the electron transport rate decreased significantly,but the non-photochemical quenching coefficient increased significantly,indicating an increasing heat dissipation of light energy.The leaves of P.sepium had a strong ability to adapt to drought stress by regulating photosynthetic efficiency,and showed a certain degree of plasticity and adaptability to drought stress habitat. |
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| Keywords: | Periploca sepium shell sand drought stress gas exchange parameter chlorophyll fluorescence |
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