Abstract: The in vitro morphological changes during seed germination of Vanda amesia and Cymbidium floribundum were examined by scanning elect-on microscope. During Vanda amesia seed germination, the embryo was genfrally referred as the "protocorm" and was visible to the naked eyes. The germination of Cymbidium floribundum resembled to that of Vanda amesia except that rhizome was formed after germination and leaf development was poorer. Leaves assumed scumed scale-shape and tightly covered the meristem of the rhizome. Photos of scanning electron microscope revealed that each hair was an outgrowth of a papila protruding out from the outer wall of the epidermal cfll, thus equivalens to a roothair.

Key words: Vanda amesia, Cymbidium floribundum, Protocorm, Rhizome, Root hair, Shoot differentiation, Cotyledon

摘要： 兰种子发芽之后形成原球茎与根状茎,前者以亚美万代兰,后者以多花兰为材料进行扫描电镜观察。多花兰种子发芽初期,与亚美万代兰相似,但分化子叶的能力较差,在暗培养下,只形成鳞片状叶,紧贴在根状茎的分生组织上。根状茎只有转入光培养才有茎叶分化。兰种子发芽时的毛状物,在电子显微镜下观察,其形态与根毛较接近。

关键词: 亚美万代兰, 多花兰, 原球茎, 根状茎, 根毛, 茎叶分化, 子叶