德保苏铁茎的解剖学研究

对德保苏铁茎、叶柄的解剖构造进行观察,结果表明:(1)德保苏铁的茎由周皮、皮层、维管束、髓四部分构成。木栓层的细胞壁完全栓化;皮层大而显著,皮层细胞一般较小,富含淀粉,分布有粘液道;维管束通常较小,主要集中在皮层和髓之间的狭窄区,排列呈环形,具2生长环;少部分稀疏地散生在皮层薄壁细胞之间。(2)叶柄由表皮、绿皮层、下皮层、基本组织、维管束、髓组成。表皮细胞1层,细胞外壁角质化;绿皮细胞2层,有叶绿体;下皮层的厚壁细胞,大小不一,细胞壁强烈增厚;维管束散生,属外韧维管束,排列呈环形,内有零星分布的维管束。

Research on anatomy of the stem of Cycas debaoensis

This paper studies the anatomy of stem and leaf stalk of Cycas debaoensis. The results show that:(1)The stem of C.debaoensisis composed of four parts,including periderm,coetex,vascular vundle and marrow. The phellem cell is completely suberizated. The cortex is big and obvious. The cell of cortex is comparably small,full of amylum,scatting with secretony cavity;The vascular bundle is very small,it focuses on the narrow area between cortex and marrow,arranging like a ring with two growing loop. A little of them are sparsely scatted in the cortex tissue. (2)Leaf stalk is made up of epidermis,shagreen cell,uder-cortex,basic tissue,vascular and medulla. The epidermis is one layer with keratinized cell wall. The shagreen cell is two layer with chlorophyll. The thick-cell wall in the under-cortex are in different shapes. The thickness of the cell wall are strorgly added. The vascular bundle are sparselp scattered and belongs to collateral bundle,ringing with spotty vascular bundle.