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林业科学 ›› 2015, Vol. 51 ›› Issue (2): 129-136.doi: 10.11707/j.1001-7488.20150216

• 研究简报 • 上一篇    下一篇

遮荫对中华蚊母树苗期生长及光合特性的影响

刘泽彬, 程瑞梅, 肖文发, 郭泉水, 王娜   

  1. 中国林业科学研究院森林生态环境与保护研究所 国家林业局森林生态环境重点实验室 北京 100091
  • 收稿日期:2013-10-10 修回日期:2014-12-01 出版日期:2015-02-25 发布日期:2015-03-11
  • 通讯作者: 程瑞梅
  • 基金资助:

    十二五林业科技支撑计划课题"长江流域防护林体系整体优化与调控技术"(2011BAD38BO4)。

Effects of Shading on Growth and Photosynthetic Characteristics of Distylium chinense Seedlings

Liu Zebin, Cheng Ruimei, Xiao Wenfa, Guo Quanshui, Wang Na   

  1. Key Laboratory of Forest Ecology and Environment, State Forestry Administration Research Institute of Forest Ecology, Environment and Protection, CAF Beijing 100091
  • Received:2013-10-10 Revised:2014-12-01 Online:2015-02-25 Published:2015-03-11

摘要:

【目的】探讨不同遮荫环境对中华蚊母树苗期生长及光合特性的影响,分析苗期中华蚊母树对不同遮荫环境的适应性,为城市园林建设中合理进行乔、灌木布置提供科学依据。【方法】采用遮荫网,设置全光CK、中度遮荫L1(25%全光)和重度遮荫L2(7%全光)3种光环境,测定不同光环境下苗期中华蚊母树生长、光合以及叶绿素荧光参数。【结果】经过60天的遮荫处理,L1和L2植株基径增量和比叶质量显著低于CK植株,而L1和L2植株叶长和最大叶宽显著高于CK植株;受遮荫影响,L1植株株高增量显著高于CK植株,而L2植株株高增量与CK植株差异不显著;遮荫导致了苗期中华蚊母树叶片最大净光合速率、暗呼吸速率、光补偿点以及光饱和点等光合指标降低,且随着遮荫程度增加,这些光合指标的降低程度也逐渐增加,L1植株叶片最大净光合速率、暗呼吸速率、光补偿点以及光饱和点分别比CK植株降低了11.8%,46.3%,48.6和15.5%,L2植株叶片最大净光合速率、暗呼吸速率、光补偿点以及光饱和点分别比CK植株降低了35.2%,65.7%,64.2%和20.4%;遮荫对苗期中华蚊母树叶片表观量子效率的影响并不明显,经过60天遮荫处理,L1和L2植株叶片表观量子效率均与CK植株差异不显著;遮荫使苗期中华蚊母树叶片最大光化学效率有所增加,其中L1植株叶片最大光化学效率显著高于CK植株,而L2植株叶片最大光化学效率与CK植株差异不显著;遮荫降低了苗期中华蚊母树叶片光化学猝灭和电子传递速率,L1植株叶片光化学猝灭和电子传递速率均显著低于CK植株,L2植株叶片光化学猝灭显著低于CK植株,但叶片电子传递速率与CK植株差异不显著;遮荫虽然降低了苗期中华蚊母树叶片的非光化学猝灭,但L1和L2植株叶片非光化学猝灭均与CK植株差异不显著。【结论】苗期中华蚊母树具有很强的耐荫能力,遮荫可使其对自身形态结构进行调整,如增加株高、叶长和叶宽和降低比叶质量等,以及叶片光合生理的调整,如降低叶片光补偿点和光饱和点、维持较高的表观量子效率和最大光化学效率等,来尽可能多地捕获光能及提高对弱光的利用率,同时也能使其减少对基径生长的能量分配以及降低叶片暗呼吸速率来减少对光合产物的消耗。因此,在进行城市园林建设时,可以尝试将中华蚊母树作为一种耐荫景观树种与乔木进行复合搭配栽植。

关键词: 中华蚊母树, 遮荫, 生长, 光合特性, 叶绿素荧光

Abstract:

【Objective】Distylium chinense as a shrub will be inevitably subjected to low light conditions when used in urban landscapes, it is essential to understand how the low light conditions affect the growth of D. chinense. A shading experiment was conducted to study the effects of different shading intensities on growth, photosynthesis and chlorophyll fluorescence parameters of D. chinense seedlings and to analyze the responses of the seedlings to the shading.【Method】Three intensities of artificial shading were installed, full light (Control; CK), moderate shading (25% of full light; L1) and heavy shading (7% of full light; L2), and the growth, photosynthesis and chlorophyll fluorescence parameters of D. chinense seedlings under different shading intensities were measured. 【Result】After shading for 60 d, the increment of basal diameter and specific leaf weight in L1 and L2 were decreased significantly, and leaf length and maximum leaf width in L1 and L2 were increased significantly compared to the CK. The increment of plant height was significantly larger in L1 than in CK, but no significant difference was found between L2 and CK. The shading has led to decline of maximum net photosynthetic rate, dark respiration rate, light compensation point and light saturation point, and the decline gradually intensified with the intensity of shading. Compared to the CK, the maximum net photosynthetic rate, dark respiration rate, light compensation point and light saturation point in L1 decreased by 11.8%,46.3%,48.6%, and 15.5%, respectively, and the maximum net photosynthetic rate, dark respiration rate, light compensation point and light saturation point in L2 decreased by 35.2%,65.7%,64.2%,and 20.4%, respectively. The effect of shading on apparent quantum efficiency was not significant, no significant differences in apparent quantum efficiency were found between the shading treatments (L1 and L2) and the CK after shading for 60 d. Compared to the CK, the shading had resulted in significant increase of the maximal photochemical efficiency in L1 but not in L2, and significant decrease of the photochemical quenching and electron transport rate in L1, significant decrease of the photochemical quenching but not the electron transport rate in L2.Although shading has resulted in decreases of non-photochemical quenching, but not at a significant level compared to the CK. 【Conclusion】Results indicated that D. chinense seedlings had a strongly shade-tolerance. Shading allowed the trees to capture more energy and to improve the efficiency of utilizing low light intensity through regulating the morphological characteristics (such as increasing plant height, leaf length and maximum leaf width and reducing specific leaf weight) and photosynthetic physiological characteristics (such as reducing the light compensation point and the light saturation point and maintain a relatively high apparent quantum efficiency and maximal photochemical efficiency), and also to reduce the consumption of photosynthetic products through reducing the energy distribution for the growth of basal diameter and the dark respiration rate of leaves. Therefore, an attempt might be made to grow D. chinense as a shade-tolerant tree species together with other arbor trees in urban landscapes.

Key words: Distylium chinense, shade, growth, photosynthetic characteristics, chlorophyll fluorescence

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