刺槐幼苗根茎过渡区初生维管组织的观察

Primary Vascular Tissues of the Root-stem Transition Zone in Robinia pseudoacacia L. Seedlings

对不同苗龄(1-12d)的刺槐(Robinia pseudoacacia L.)幼苗进行观察,比较了其初生维管组织的发育变化。结果表明:根中的初生维管组织借助下胚轴过渡到子叶中,而茎中的初生维管组织与下胚轴中的维管组织仅是简单的连接。这与Esau等认为幼苗的外部形态可以分为根-下胚轴-子叶和上胚轴苗两个系统的观点是一致的。本研究亦证实了可以将刺槐幼苗的外部形态描述为这两个系统,二者的维管组织只是简单的连接,不存在过渡。

The development of primary vascular tissues of root-stem transition region was studied in Robinia pseudoacacia L. seedlings of 1-12 days using sequential paraffin section. The primary vascular tissues of roots are connected with the cotyledons via the hypocotyl. The results support the viewpoints ofEsau et al. that the whole seedling ofR. pseudoacacia L. is divided into two systems of the root-hypocotyl-cotyledon and the epicotyl, and there is only a simple linkage between the vascular tissues of stem and the hypocotyl without any transition.