Primary Vascular Tissues of the Root-stem Transition Zone in Robinia pseudoacacia L. Seedlings
刺槐幼苗根茎过渡区初生维管组织的观察

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 of Esau et al. that the whole seedling of R. 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.