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    种长白山高山杜鹃叶片结构及其对环境的适应性

    Leaf structural characteristics of three wild Rhododendron plants and their adaptability to Changbai Mountains, northeastern China.

    • 摘要: 依托扫描电子显微技术,研究了长白山高山珍稀濒危植物牛皮杜鹃、毛毡杜鹃及苞叶杜鹃的叶片结构,分析了其对高山环境的适应性。结果表明:3种杜鹃叶片均为异面叶,具表皮附属物。上表皮由1~2层细胞组成,有角质层,无气孔器;下表皮由1层细胞组成,有气孔器分布。栅栏组织细胞排列紧密有2~8层,海绵组织细胞间隙大,中脉维管束为圆形外韧型。此外,叶片的表皮附属物类型,气孔器特点,海绵组织细胞排列方式等差异明显。3种杜鹃植物的扫描电镜结构特征,既为种间鉴别提供了依据,也反映了其对高山环境的适应性。

       

      Abstract: Based on the scanning electron microscopy method,the leaf structural characteristics of Rhododendron chrysanthum, R. confertissimum and R. redowskianum in Changbai Mountains were analyzed,and the results were used to reveal the leaf structural characteristics adapted to the Changbai Mountain environments. Microscopic results revealed that the leaf blades covered with epidermis trichomes were typical backabdomen bifacial types, the upper epidermis formed by one or two layer of cells was covered with thicker cuticle. There were many stomas distributed in the lower epidermis formed by one layer of small cells, while the upper epidermis had not. The palisade tissue was formed by two to eight layers of long column cells that lined up densely, and cells of the spongy tissue lined up loosely and had the bigger cell intervals. The type of middle vein bundle was collateral vascular bundle. The different structures are the characteristic manifestation of ecological tissue adaptation among communities,and they also provide discriminate characteristics in taxonomy.

       

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