百里杜鹃杜鹃属13种植物叶片解剖结构的生态适应性

Leaf Anatomical Characters and Its Ecological Adaptation of 13 Species of Rhododendron in Baili Azalea Area

贵州百里杜鹃国家森林公园是现已发现的世界上最大且连续分布的天然野生杜鹃花群落。依托生物显微制片技术、数理统计分析方法,研究了采集自百里杜鹃林区的13种杜鹃属植物的叶片解剖特征及其生态适应性,并对其解剖结构特征进行了聚类分析及因子分析。结果表明:①叶片不同解剖性状在种、种群间的变化不同步,其中叶片的海绵组织厚度、叶片厚度、中脉厚度、栅海厚度比以及第1层上表皮细胞长宽比几项解剖特征变异幅度>50%,显示这些性状更易受环境饰变,是生态适应性状;而气孔密度、气孔长宽比等性状差异小,属相对稳定的系统演替性状。②马银花、光柱迷人杜鹃等具有发达的机械组织,显示对干燥环境的适应;而迷人杜鹃、银叶杜鹃等海绵组织发达,显示对中高山凉湿环境的适应。③叶片解剖结构在种间、种群间有不同程度差异,这是它们适应各自生境的结果。映山红种内差异较大,反映出它对环境变化有较强的响应能力。④主因子聚类分析结果将研究的13种杜鹃属植物分为3类,分类与杜鹃属在系统学上的分类一致。

Natural Rhododendron is wildly distributed in One Hundred Miles Azalea Park, which is the biggest and continuous Rhododendron community in the world.Based upon the ecoanatomieal methed,leaf anatomical characters of 13 species of Rhododendron in Baili Azalea Area were analyzed and compared with SPSS and PCA,and cluster analysis and factor analysis were also used to analyze its anatomical structure.The results showed that （1） Anatomical characteristics of leaves changed non- synchronously inter or among communities （variation range of thickness of spdngy tissue and midrib, the percentage of palisade and spongy, tissue,the aspect ratio of epidermal cells was more than 50% ） which demonstrated that these characteristics were easily affected by environment and was considered as ecological adaptability features; while stomatal density, stematal aspects ratio varied slightly. （2）Rhododendron ovattLrn and Rhododendron agashun vat. pennivenium has developed mechanic tissues to demonstrate its adaptability to drought;while R. agastum and Rh. argyrophyllum has developed spongy tissue to show its adaptability to cool and humid environment in high mountains. （3）The difference of leaf anatomical structures inter and among communities was resulted from their adaption to own habitats. Rhododendron simsii Planch varies significantly inter community demonstrated its strong response capacity to different habitats.（4）13 species of Rhododendron in Baili Azalea Area were divided into three eategories,which is in accordance with the classification of Rhododendron in systenkatology.