| 摘要: |
| 为深入研究闽楠幼苗在极弱光环境下的可塑性及生存策略,该文以2年生闽楠幼苗为试验材料,通过人工遮阴方式模拟不同光环境(100%、35%和10%透光率),测定不同处理下闽楠幼苗叶片表观形态、解剖结构和光合生理等参数,探讨幼苗形态、生理可塑性与光适应的内在联系。结果表明:(1)闽楠幼苗的叶长、叶宽、叶面积和比叶面积(SLA)均随着光强的减弱而增加,叶片厚度、栅栏组织厚度、海绵组织厚度和栅海比值(栅栏组织厚度/海绵组织厚度)等均以10%透光率下最小。(2)35%透光率的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、光能利用率(LUE)、光系统Ⅱ(PS Ⅱ)的光化学淬灭系数(qp)、非光化学淬灭系数(NPQ)、有效光合量子产量(Fv'/Fm')及潜在光化学效率(Fv/Fo)等均显著高于100%和10%透光率处理。(3)叶绿素a、叶绿素b、类胡萝卜素、叶绿素总量及最大光化学效率(Fv/Fm)等均随着光强的减弱而增加,但叶绿素a/b随着光照强度的减弱而降低。(4)幼苗结构和生理表型可塑性指数显示,光合色素含量特征>形态特征>光合特征>解剖结构特征>叶绿素荧光参数特征,其中叶面积、SLA、Pn、Gs、LUE及光合色素含量的表型可塑性指数在0.455～0.755之间。综上所述,闽楠幼苗不适宜在全光照下生长,在35%左右的透光率下表现良好; 在10%透光率下,闽楠叶片通过增加叶面积、SLA、Pn及光合色素含量来提高对光能的捕获; 弱光下闽楠幼苗主要通过调节光合色素含量与形态的可塑性,协同解剖结构、光合生理及叶绿素荧光参数可塑性的变化来适应弱光环境。该研究可为今后闽楠栽培管理提供理论依据。 |
| 关键词: 弱光, 闽楠幼苗, 叶片形态, 光合生理, 可塑性 |
| DOI：10.11931/guihaia.gxzw202112012 |
| 分类号:Q945 |
| 文章编号:1000-3142(2024)03-0501-09 |
| Fund project:国家自然科学基金(31870613); 贵州高层次创新人才计划—“百”层次人才项目(黔科合平台人才 [2016]5661)。 |
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| properties of artificial mixed forests of Pinus elliottii |
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AN Jing1,2, WEI Xiaoli1,3*, YAO Yao1, JIN Nianqing1, WU Gaoyin1, WANG Xiao1
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1. College of Forestry, Guizhou University, Guiyang 550025, China;2. Geography &3.Environmental Science College, Guizhou Normal
University, Guiyang 550025, China;4.3. Institute for Forest Resources and Environment of Guizhou, Guiyang 550025, China
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| Abstract: |
| The purpose of this study is to explore the survival strategy of Phoebe bournei seedlings in natural communities under extremely low light environment. Two-year-old seedlings of P. bournei were used as experimental materials.Leaf morphology, anatomical structure and photosynthetic physiological characteristics of P. bournei seedlings were measured by simulating different light environments(100%, 35% and 10% light transmittance), and to explore the internal relationship between seedling morphology, physiological plasticity and light adaptation. The results were as follows:(1)The leaf length, leaf width, leaf area and specific leaf area(SLA)of seedlings increased with the decrease of light intensity. The leaf thickness, palisade tissue thickness, spongy tissue thickness and palisade/spongy(palisade tissue thickness/spongy tissue thickness)of 10% light transmittance were the minimum.(2)The net photosynthetic rate(Pn), stomatal conductance(Gs), transpiration rate(Tr), light utilization efficiency(LUE), photochemical quenching coefficient(qp), non photochemical quenching coefficient(NPQ), effective photosynthetic quantum yield(Fv'/Fm')and potential photochemical efficiency(Fv/Fo)of photosystem Ⅱ of 35% light transmittance were significantly higher than those of 100% and 10% light transmittances.(3)Chlorophyll a, chlorophyll b, carotenoids, total chlorophyll and maximal photochemical efficiency(Fv/Fm)all increased with the decrease of light intensity, but chlorophyll a/b decreased with the decrease of light intensity.(4)The phenotypic plasticity indexes of seedling structure and physiology showed that photosynthetic pigment content characteristics > morphological characteristics > photosynthetic characteristics > anatomical structure characteristics > chlorophyll fluorescence parameter characteristics, among which, the phenotypic plasticity indexes of leaf area, SLA, Pn, Gs, LUE and photosynthetic pigment content ranged from 0.455 to 0.755. To sum up, P. bournei seedlings are not suitable to grow under full light, and perform well under about 35% light transmittance; under extremely low light with 10% light transmittance, P. bournei leaves can improve light energy capture by increasing leaf area, SLA, Pn and photosynthetic pigment content; the seedlings of P. bournei mainly adapt to the low light environment by adjusting the plasticity of photosynthetic pigment content and morphology, coordinating with the changes of anatomical structure, photosynthetic physiology and chlorophyll fluorescence parameter plasticity. This study can provide theoretical reference for the management and selection of light environment of P. bournei for future cultivation. |
| Key words: low light, Phoebe bournei seedling, leaf morphology, photosynthetic physiology, plasticity |
