表型可塑性是指同一基因型的生物个体在不同环境条件下产生不同表型的特性, 这一特性促使物种适应异质环境, 具有更宽的生态幅。居群和物种水平广义的表型可塑性研究可揭示植物在自然环境中的生态意义并丰富对植物种群分布的了解。华中五味子(Schisandra sphenanthera)是一种资源严重减少的常用野生药材物种, 对其进行研究和保护非常必要。叶是华中五味子主要的光合作用器官, 随环境改变叶表型有很大变化, 因此从居群水平上对华中五味子叶表型可塑性进行分析, 揭示叶表型可塑性大小, 探究环境因子对叶表型的影响, 可为华中五味子的保护提供依据。该研究运用GIS技术从较大尺度(9省市26县27个居群)对华中五味子叶表型可塑性进行分析, 并用表型可塑性指数和变异系数2种方法对叶表型可塑性进行评价, 运用隶属函数和最大熵模型将3类(土壤、气候和地形)13个环境因子对叶表型的影响进行分析。结果表明, 华中五味子7个叶表型(叶长、叶宽、叶柄长、叶面积、叶形指数、叶齿数和二级叶脉数)均存在可塑性, 其中叶面积可塑性最大, 叶形指数可塑性最小。3类环境因子中对叶表型影响最大的为土壤因子, 气候因子次之, 最小为地形因子。权重分析显示, 土壤全钾含量对叶长和叶面积影响最大, 有机碳含量、海拔、土壤全磷含量、坡度和年降水量分别对叶宽、叶柄长、叶形指数、叶齿数和二级叶脉数影响最大。研究结果表明, 对多个叶表型有影响的5个共有重要因子为土壤全钾含量、全磷含量、有机碳含量、年降水量和坡度, 它们与对应叶表型间的隶属函数多为高斯型, 具有最优值, 可通过人工控制达到最优值来促进其生长。该结果为华中五味子野生抚育和迁地种植提供理论参考。

With phenotypic plasticity, plant individuals with the same genotype show different phenotypes in different environments. The characteristic lets species adapt to heterogeneous environments and have wider niches. Broad studies of phenotypic plasticity at the population and species levels are revealing the ecological significance of wild plants and also enrich the understanding of population distribution. Schisandra sphenanthera is a main species used for wild medicinal materials but is becoming scarce. Research and protection of the species is necessary. Leaves are the main organs of photosynthesis of S. sphenanthera, whose phenotypes vary with environmental changes. Analysis of phenotypic plasticity of leaves at the population level will reveal the plasticity of leaves, explore the effect of environmental factors on leaf phenotypes and provide the basis for the protection of S. sphenanthera. In this study, we analyzed the phenotypic plasticity of S. sphenanthera leaves on a large scale (9 provinces/cities, 26 counties, 27 populations) by using GIS technology. The 2 methods we used were phenotypic plasticity index and variation coefficient. We analyzed the effect of environmental factors on leaf phenotypic plasticity by using membership function and maximum entropy modeling. The environmental factors were of 3 types (edaphic, climate and topographic), including 13 factors. The results suggested that 7 kinds of leaf phenotypes (leaf length, leaf width, leaf petiole length, leaf area, leaf shape index, number of leaves teeth and number of secondary veins) all had plasticity. The plasticity of the leaf area was the greatest and leaf shape the least. The effect of the edaphic factor was the greatest among the environmental factors, followed by the climatic factor and the topographic factor. Weight analysis showed that total soil kalium content had the greatest effect on leaf length and area. Total organic carbon content, altitude above sea level, total phosphorus content, slope and annual precipitation had the greatest effect on leaf width, petiole length, shape index, number of leaf teeth and number of secondary veins, respectively. Five common important factors with effects on multiple leaf phenotypes including total soil kalium content, total phosphorus content, total organic carbon content, annual precipitation and slope. The membership functions of common important factors and their corresponding leaf phenotype were almost Gaussian-type and had optimum value. Achieving optimum value by manual control could promote S. sphenanthera growth. This study provided reference data for wild and ex situ cultivation of S. sphenanthera.