长蕊甜菜营养器官解剖学观察

采用石蜡切片、整体装片等方法对长蕊甜菜的根、茎、叶等器官的显微结构进行解剖学观察.结果显示:长蕊甜菜根为不断增粗的肉质根,维管束初生木质部初期为四原型,随着根的增粗,初生木质部发展为多原型;茎维管形成层的活动受季节影响不大,生长轮不明显;靠近髓部的木射线细胞可以发生次生增生,产生大量的薄壁细胞,导致茎中部形成两个髓心;叶表皮细胞为较规则的几何形状,气孔为平列型,副卫细胞2~4个,单面叶.

Anatomical Observation on Vegetative Organs of Melientha longistaminea

Anatomical observation on the vegetative organs(root, stem and leaf) of Melientha longistaminea were made with microscope by means of paraffin-cut sections and integral loading methodology.It was showed by the observation that: The root of M.longistaminea belonged to meaty root system which would continuously grow in diameter.The primary xylem of vascular strand was tetrarch at the initial stage;along with the taproot thickening,bundles of the primary xylem became polyarch.The growth of vascular strand cambium was not significantly influenced by the change of seasons,with inconspicuous growth rings.There were two piths in the central part of the stems because of the secondary accretion of wood ray cells adjacent to the first pith center,forming large quantity of parenchyma cells.This species had solitary leaves,and the leaf epidermis cells were regularly geometric in shapes,with paracytic type of stoma and 2 to 4 subsidiary cells around each stomata.