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草业学报 ›› 2021, Vol. 30 ›› Issue (12): 103-116.DOI: 10.11686/cyxb2020466

• 研究论文 • 上一篇    

不同光强对4种鸭跖草科植物茎秆性状和力学特征的影响

陈斌1(), 刘筱玮1, 贾琳2, 李子葳1, 杨宇佳1, 岳莉然1, 何淼1()   

  1. 1.东北林业大学园林学院,黑龙江 哈尔滨 150040
    2.东北林业大学林学院,黑龙江 哈尔滨 150040
  • 收稿日期:2020-10-19 修回日期:2020-11-23 出版日期:2021-11-11 发布日期:2021-11-11
  • 通讯作者: 何淼
  • 作者简介:Corresponding author. E-mail: hm2017148@126.com
    陈斌(1994-),男,江苏徐州人,在读博士。E-mail: cb20200103_dr@163.com
  • 基金资助:
    国家重点研发计划项目(2018YFD1000406);中央高校基本科研业务费专项资助基金(2572014BA22)

Effects of different light intensities on stem characters and mechanical traits of four Commelinaceae plants

Bin CHEN1(), Xiao-wei LIU1, Lin JIA2, Zi-wei LI1, Yu-jia YANG1, Li-ran YUE1, Miao HE1()   

  1. 1.Department of Landscape Architecture,Northeast Forestry University,Harbin 150040,China
    2.Department of Forestry,Northeast Forestry University,Harbin 150040,China
  • Received:2020-10-19 Revised:2020-11-23 Online:2021-11-11 Published:2021-11-11
  • Contact: Miao HE

摘要:

为探究不同光强下鸭跖草科植物茎秆性状和力学特征的变化规律,以紫鸭跖草、花叶水竹草、吊竹梅和绿叶水竹草的茎段扦插苗为试验材料,通过遮光网设置5种光强梯度(分别为自然光强的100%、75%、50%、25%、5%)进行试验,研究不同光强对4种植物茎秆形态性状、解剖结构和力学特征的影响。结果表明:随光强的降低,4种植物节间长显著增加(P<0.05),比茎重显著降低(P<0.05),除紫鸭跖草的茎生物量无显著变化外,其他3种植物的茎生物量均呈先增加后降低趋势;不同的光强对4种植物的表皮厚度、皮层厚度、维管束直径、髓直径以及茎粗产生了不同的影响,但各组织结构与茎粗的比值保持相对稳定,同时光强降低使4种植物的髓细胞长和皮层细胞长显著增加(P<0.05),髓细胞宽和皮层细胞宽显著降低(P<0.05);4种植物的弯折性能和抗压强度以及紫鸭跖草、吊竹梅和绿叶水竹草的组织结构强度随光强的降低而显著降低(P<0.05)。Pearson相关性分析结果表明,比茎重、表皮厚度、皮层厚度、维管束直径、髓直径、茎粗、皮层细胞宽、髓细胞宽与弯折性能呈极显著正相关(P<0.01),髓细胞宽与组织结构强度呈极显著正相关(P<0.01),比茎重、表皮厚度、髓直径、髓细胞宽与抗压强度呈极显著正相关 (P<0.01)。综合上述结果,4种植物可以通过增加茎生物量的分配、节间长的方式在弱光环境中获取有限的光资源,但茎生物量的增加存在明显的阈值,且与节间长的增加呈失衡状态,导致比茎重的降低以及茎秆各解剖结构发生改变,造成4种植物的弯折性能、组织结构强度和抗压强度降低,隶属函数分析表明不同光强下花叶水竹草和吊竹梅的茎秆特性较优,其次为绿叶水竹草,最差的为紫鸭跖草。

关键词: 光强, 鸭跖草科植物, 茎秆性状, 力学特征

Abstract:

This study explored the patterns of change in stem characters and mechanical traits in Commelinaceae plants grown under different light intensities. Ramets of Commelina purpureaTradescantia fluminensis ‘Variegata’, T. zebrina and T. fluminensis ‘Vairidia’ propagated from stem cuttings were used as experimental material. Shading net was used to create a series of five light levels of 100% natural light intensity, 75% natural light intensity, 50% natural light intensity, 25% natural light intensity and 5% natural light intensity. Stem morphological characters, anatomical structure and mechanical traits were measured under the different light levels. It was found that: As the light intensity decreased, plant internode length of the four taxa increased significantly (P<0.05). Conversely, decrease in light intensity led to significant decrease in the specific stem weight (P<0.05). Apart from C. purpurea, which showed no significant change, stem biomass was greatest at medium light levels in the taxa studied. Different light intensities had different effects on stem epidermis thickness, cortical thickness, vascular bundle diameter, medulla diameter and stem diameter. However, the relationship between internal tissue structure and stem thickness remained relatively stable across the range of light intensities. Reduced light intensity led to a significant increase in cortical cell length and medulla cell length of the four taxa (P<0.05), but also to a significant decrease in the cortical and medulla cell widths (P<0.05). The resistance to bending and compressive strength of all taxa and the organizational density of C. purpurea T. zebrina and T. fluminensis ‘Vairidia’ significantly decreased (P<0.05) when light intensity decreased. Pearson correlation analysis showed that specific stem weight, epidermis thickness, cortical thickness, vascular bundle diameter, medulla diameter, stem diameter, cortical cell width and medulla cell width were all significantly correlated with resistance to bending (P<0.01). Medulla cell width was significantly correlated with organizational density (P<0.01), while specific stem weight, epidermis thickness, medulla diameter and medulla cell width were significantly correlated with compressive strength (P<0.01). These results indicate that the four studied taxa were able to obtain limited light resources in low-light environments by increasing their stem biomass and plant internode length. The increase of stem biomass has obvious limitations. These changes led to an unbalanced state with the increased plant height and internodes. This not only resulted in decreases of specific stem weight and changes of stalk anatomical structure, but also reduced stem rigidity, organizational density and compressive strength. A membership function analysis showed that the stalk characteristics of T. fluminensis ‘Variegata’ and T. zebrina were superior under a range of light intensities, followed by the T. fluminensis ‘Vairidia’, while C. purpurea was the worst.

Key words: light intensity, Commelinaceae, stem characters, mechanical traits