华中五味子叶片形态结构的可塑性研究

Lamina Morphological and Structural Plasticity of Schisandra Sphenanthera

分别对产自安徽黄山和甘肃文县的两个华中五味子种群不同发育阶段叶片的形态解剖特征进行比较,讨论了叶片表型可塑性及其生态学意义.研究结果表明:1)在种群水平上,叶片形态结构随环境条件的变化表现出一定的环境可塑性,文县种群表现出相对的旱生特征:叶片小而厚、栅栏组织发达;黄山种群则表现出相对的湿生特征:叶片大而薄、栅栏组织较薄、海绵组织相对发达;这是叶片对水分条件随地理分布而表现出的空间异质性的适应策略;2)在个体水平上,叶片形态结构随发育阶段的变化而表现出一定的发育可塑性,下层叶表现出典型的阴生叶特点:叶片薄、气孔密度较小、栅栏组织极不发达、栅栏细胞椭圆形或漏斗形、海绵组织发达;中、上层叶表现出阳生叶特征:叶片较厚、气孔密度大、栅栏组织相对较为发达、栅栏细胞长柱形.这种发育可塑性是叶片对光照条件随个体发育而表现出的时间异质性的一种适应策略.

To investigate the phenotypic plasticity and its ecological significance, lamina morphological and anatomic characteristics of Schisandra sphenanthera in different developmental stages, sampling from two populations located in Huangshan, Anhui, and Wenxian, Gansu, respectively, were examined. The results showed that： 1 ） In the population level, lamina morphological and anatomic characteristics showed great environmental plasticity according to the variation of local environment, leaves from Wenxian population characterized as xerophytic structure relatively, with smaller and thicker lamina and more developed palisade tissue, while those from Huangshan population showed relative wet characteristics such as larger and thinner lamina and less developed palisade tissue, it is one of the strategies for S. sphenanthera to adapt to the heterogeneous water condition due to different geographic distribution. 2） In the individual level, lamina morphological and anatomic characteristics showed great developmental plasticity in different developmental stage, leaves from lower layer of the shoots share the characteristics of the shade leaves as thinner leaf blade, lens - like cells in upper epidermis, undeveloped palisade tissue consisted of irregular or funnel cell, developed and compacted spongy tissue, While those from middle and upper layer of the shoots share features of sun leaves such as thicker lamina, developed palisade tissue with cylinder palisade cell which arranged densely, thinner spongy tissue loosely composed by smaller ceils, this is one of the adaptive strategies for S. sphenanthera to the heterogeneous sunlight supply in different developmental stages.