垂序商陆幼苗及其过渡区维管系统的解剖学研究

采用常规石蜡制片手段对垂序商陆幼苗进行形态解剖学研究.结果表明:垂序商陆幼苗类型为木兰型.根的初生结构由表皮、皮层和中柱组成,四原型;茎由表皮、皮层和维管柱构成,维管柱包括维管束、髓和髓射线3部分;子叶叶肉分化不明显,初生叶栅栏组织和海绵组织较为发达;幼苗过渡区维管系统属于“根—下胚轴—子叶”形式,过渡区位于下胚轴基部.

Anatomical Studies on the Vegetative Organs and Transition Vascular System of Phytolacca A- mericana Seedling

An anatomical study was conducted on the vegetative organ of Phytolacca Americana by the common plant paraffin section. The results showed that the seedling type of Phytolacca Americana was Magnolia Type. The root was diarch, which consisted of epidermis, cortex and stele. The stem consisted of epidermis, cortex and vascular cylinder. The vascular cylinder contained vascular bundle, pith and pith ray. The differentiation of cotyledon mesophyll was not obvious, however, the palisade tissue and the spongy tissue of primary leaf was well-developed. Transition vascular system was＂ root-hypocotyl-cotyledon＂ form and the transition zone was formed in the base of the hypocotyl.