桂花根和茎的形态与解剖研究

以籽银桂(Osmanthus fragrans ‘Ziyingui’)和日香桂(O.fragrans ‘Rixianggui’)为材料,采用石蜡切片技术,研究了桂花营养器官根和茎的形态特征与解剖结构。结果表明,桂花根的初生结构由表皮、皮层和维管柱组成。表皮上有根毛,表皮细胞长轴与根圆周垂直,有明显的外皮层和内皮层;维管柱(中柱)为五原型。次生生长旺盛,次生韧皮部中有少量的韧皮纤维;茎的初生结构由表皮、皮层和维管柱组成,表皮上有少量腺毛分布;外韧维管束;次生韧皮部中分布有较多的韧皮纤维,呈完整的一环,增加了茎的柔韧性。

Morphological and Anatomical Studies on the Root and Stem of Osmanthus fragrans Lour

Applying O. fragrans 'Ziyingui'and O. fragrans 'Rixianggui'as experimental materials, the author studied the morphological features and anatomical structures of roots and stems of O. fragrans by Parafin method. The primary structure of O. fragrans root consists of epidermis, cortex and vascular cylinder (stele). Epidermis has many single cell hairs, i. e. root hairs. The long axes of epidermis cells are vertical to the circumference of root. Exodermis and endodermis exist obviously. Endodermis has Casparian band. The primary 2 xylem of O. fragrans root has 5 ridges of protoxylem, named as pentarch root. The secondary structure of O. fragrans root consists of secondary xylem, secondary phloem, vascular cambium and periderm. The primary structure of O. fragrans stem also consists of epidermis, cortex and vascular cylinder. There are a few of glandular hairs on its epidermis. More vascular bundles exist in its primary structure. They are small or large, named as collateral bundle. The stem's pith owns more space observed from its transverse section. The secondary structure of O. fragrans stem is composed of secondary xylem, secondary phloem, vascular cambium and periderm. There is much more phloem fibre in the secondary phloem. Phloem fibre distributes around the stem, forms a total fibre ring. This structure improves the pliancy of O. fragrans stem.