荆条和多花胡枝子叶片形态和光合生理特性的耐阴适应性研究

Shade Tolerance of Leaf Morphology and Photosynthetic Physiological Characteristics of Vitex negundo var. heterophylla and Lespedeza floribunda

荆条和多花胡枝子是北京地区典型的乡土植物,具有耐寒、耐热、耐瘠薄等较强的综合抗性,但其耐阴适应性反应及生理机理仍不清楚。通过测定植株在不同遮阴处理下的叶片形态和光合生理特性指标,分析其耐阴的适应性变化。结果表明,2种植物都具有较强的耐阴性,在不同遮阴处理条件下,叶片面积、厚度、含水量、气孔密度和导度、净光合速率、叶绿素含量变化等叶片形态和光合生理特性指标都能够对荫蔽环境产生一系列的适应性变化,维持植株正常生长。荆条对荫蔽环境的适应性能力比多花胡枝子略强。

Both Vitex negundo var. heterophylla and Lespedeza floribunda belong to typical indigenous plants of Beijing with multiple resistances, such as cold, heat, barren and so on, but their adaptability response to shade and the physiological mechanism are still not clear. In this study, the leaf morphology and photosynthetic physiological characteristics of these two plant species under different shade treatments were measured to analyze their adaptive changes to shade. The results indicate that both the plant species have strong shade tolerance, and under different shade treatments, the leaf area, thickness, water content, stomatal density and conductance, net photosynthetic rate and chlorophyll content of the two plant species change adaptively and could grow normally. Besides, Vitex negundo var. heterophylla shows a stronger adaptability to shade environment than Lespedeza floribunda.