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金松茎次生韧皮部的解剖

THE ANATOMY OF SECONDARY PHLOEM IN SCIADOPITYS VERTICILLATA (THNUB.) SIEB. ET ZUCC.

  • 摘要: 在光学显微镜和扫描电子显微镜下,金松茎次生韧皮部的结构,主要特征为:(1)轴向系统由筛胞、韧皮薄壁组织细胞、蛋白质细胞及韧皮纤维组成;径向系统为单列,稀二列的韧皮射线构成。(2)筛胞径向壁上嵌埋有许多草酸钙结晶。(3)韧皮纤维仅一种类型,径向排列1—6个细胞宽的切向带,两带之间筛胞与韧皮薄壁组织细胞层数不规则。通过我们的研究结果,支持金松属可从杉科中分离出来成立金松科的主张。

     

    Abstract: The anatomical characters of the secondary phloem of stem in Sciadopitys verticillata(Thunb.)Sieb.et Zucc.has been observed by means of both light and scanning electron microscopy. The main results are as follows:1. The axial system is composed of sieve cells, phloem parenchyma cells, albuminous cells and phloem fibers. Thc phloem rays are homogeneous, uniseriate, rarely partly biseriate.2. Many crystals of calcium oxalate are embedded in the radial walls of sieve cells.3. The thick-wall fibers form tangential bands, arranged 1—6 cells wide in radial row. Number of the tangential layers of sieve cells and phloem parenchyma cells between two fiber bands are irregular.4. No sclereids are found in the secondary phloem of main trunk.The systematic position of the genus Sciadopitys is discussed and the present study supports the view that Sciadopitys should be seperated from Taxodiaceae and independented a monotypic family, Sciadopityaceae.

     

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