凹叶厚朴茎和叶的解剖学研究

Anatommical Study on the Stem and Leaf of Magnolia biloba(Rehd.et Wils.) Cheng

采用石蜡切片法对凹叶厚朴的茎和叶的显微结构进行解剖观察,结果表明,凹叶厚朴在茎、叶轴、小叶柄的内皮层和髓中以及主脉下方的薄壁组织中都有分泌腔分布,部分细胞壁出现网状结构.凹叶厚朴的叶为异面叶,气孔仅分布于下表皮,为无规则型,栅栏组织发达.茎的初生构造中,皮层和髓的生活薄壁细胞丰富.茎的次生木质部为散孔材,导管端壁倾斜,具梯状复穿孔,木薄壁细胞稀少,呈星散分布.表明凹叶厚朴在进化中是较为原始的树种.

The results of structural botanical experiment on stem and leaf of Magnolia biloba （ Rehd. et Wils. ） Cheng show： there are secretory cavities distributed in the cortex and pith of the stem,of the rachis and the petiolule, and in the parenchyma under the main vein in the Magnolia biloba （ Rehd. et Wils. ） Cheng; in the walls of some cells there exist reticulate structures. The leaf is of dorsi-ventral leaf, and the stoma only scatter over the lower epidermis of the leaf,which belongs to anomocytic type. In the primare of the stem,the living thin-wall cells are very rich in the cortex and the pith. The secondary xylem is that of diffuse-porous wood. The vessel end wall, applanate and slopping is laddershaped compund fenestrated. The wood parenchyma is rare and has a star-scattering distribution. All these indicate that Magnolia biloba （Rehd. et Wils. ） Cheng is a more primitive species in evolution.