| 摘要: |
| 【目的】研究支持柱直径对紫萼龙吐珠（Clerodendrum speciosum）形态特征和生物量分配的影响，为其在城市园林垂直绿化中的快速攀援提供理论依据。【方法】以紫萼龙吐珠1年生扦插苗为试验材料，采用完全随机区组设计，设置3种直径支持柱（8，16，24 mm竹竿）处理，并以无支持柱为对照（CK），分析不同直径支持柱下植株的生长动态、形态特征、生物量分配及表型可塑性指数的变化规律。【结果】（1）直径8 mm支持柱上植株主茎长、节间长和叶片数均增长较快；直径16 mm支持柱上紫萼龙吐珠具有较高的自主螺旋缠绕能力，且植株通过增加叶片数和主茎长提高自主攀援能力；直径24 mm支持柱上植株的叶柄长和分枝节间长显著大于16 mm支持柱上的植株（P<0.05），自主缠绕情况较差的植株通过增加分枝的比茎长和比叶柄长、伸长节间等方式进一步搜寻外界支持物。（2）无支持柱组植株的根冠比显著大于有支持柱的植株（P<0.05），显示支持柱的存在使植株的生物量更多地分配到地上部分的枝和叶；当植株攀援外界支持柱的扭转率下降时，植株分配更多的生物量到地上部分的分枝茎和叶柄上。（3）紫萼龙吐珠在主茎水平上具有较强的形态可塑性；而在其分枝水平上，植株主要通过改变生物量的分配来适应不同的外界支持物条件。【结论】紫萼龙吐珠对不同直径支持柱表现出较强的形态和生物量可塑性，在园林实践中选取直径为8~16 mm的支持柱供其攀援更为合适。 |
| 关键词: 支持柱 紫萼龙吐珠 木质藤本 生物量 可塑性 |
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| 基金项目:广东省科技计划项目(2013B020302004);广东省研究生教育创新计划项目(2017JGXM-MS09） |
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| Effects of external support diameter on morphology and biomass allocation of Clerodendrum speciosum |
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ZHU Jinxin,WENG Shufei,LI Can,et al
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| Abstract: |
| 【Objective】This paper investigated the effects of external support diameter on morphology and biomass allocation of Clerodendrum speciosum to provide basis for its fast climbing growth in vertical greening.【Method】The changes of growth dynamics,morphological features,biomass distribution and phenotypic plasticity index of one year old C.speciosum cutting seedlings were investigated under three diameter external supports (8,16,and 24 mm bamboo) with the control (CK) without external support.【Result】(1) The growth of main stem length,internode length and leaf number of C.speciosum was fast with 8 mm support column.With the 16 mm support column,the plants had high self-spiral winding ability and the self-climbing ability increased by increasing leaf number and main stem length.The petiole length and branch internode length of the plants with 24 mm support column were significantly larger than that of the plants with 16 mm support column (P<0.05).The plant with weak self-climbing ability obtained more external support by increasing specific stem length,specific petiole length of branch,and extending internode.(2) The root-shoot ratio of plants without support column was significantly bigger than that of plants with support column (P<0.05),indicating that plants with support column would allocate more biomass to the above-ground branches and leaves.When the torsion rate of plants climbing support column decreased,the plants allocated more biomass to stems and petioles of branches.(3)C.speciosum had high morphological plasticity on the main stem level,and adapted to different external support on the branch level mainly by changing the plant biomass allocation.【Conclusion】C.speciosum showed high morphological plasticity and biomass plasticity with different diameters of support column.The columns with diameters between 8 mm to 16 mm were suggested in landscape application. |
| Key words: external support Clerodendrum speciosum liana biomass plasticity |
