五爪金龙茎的解剖结构

运用常规石蜡切片、显微观察及显微照相的方法, 对五爪金龙( Ipomoea cairica) 茎的结构进行了观察研究, 结果表明: 五爪金龙茎的解剖结构以初生结构为主, 维管形成层已经形成, 但次生结构尚不发达。通常具3～6 个空腔, 初步推断其为裂生式分泌道; 表皮外弦向壁增厚, 具角质层, 具气孔及气室;紧贴表皮内方的1～3 层和皮层最内1～3 层的细胞可能为分泌细胞; 具双韧维管束, 木质部极为发达, 导管细胞紧密排列, 围绕内韧皮部和中央的髓而成一圆周; 形成层位于外韧皮部与木质部之间; 茎中央是大型薄壁细胞构成的髓, 具簇晶。

Anatomical Structure of Stem of Ipomoea cairica (Convolvulaceae)

Anatomical structure of stem of Ipomoea cairica was observed in detail by using light microscopy . The results indicate that the anatomical structure of the stem of Ipomoea cairca compose mainly of primary structure , and the cambiums has formed , but the secondary structure is not well-developed . The stem of Ipomoea cairica usually bears 3 - 6 cavitys, which may be schizogenous secretory canals . The tangertial wall of epidermis cells gets ticker , and the epidermis has cutide, stomas and air chamber . In cortex , there are 1 - 3 layers of cells tightly next to the epidermis as well as the 1 - 3layers of cells which are deep inside cortex, both of them are secretory cells . The vascular bundles are bicollateral . The xylem is well-developed , and the vessel elements arrange so closely that they become a circle surround the phloem and pith . In the middle of stem is the pith , which composed of abundant parenchymatous cells with rhombohedral crystals .