短叶罗汉松叶结构的发育过程研究

摘要

The leaf development of Podocarpus macrophyllus var. maki Endl. started from the leaf primordium formed by the cell division in shoot apical meristem. During the leaf development, three resin canals from the inferior part of vascular bundles firstly began to differentiate, then protoxylem in vascular bundles differentiated from adaxial side to abaxial side. Meanwhile, a layer of parenchyma cells from the inferior part of protoderm developed into the sclerenchyma, which played an important role in supporting young leaves. When xylem became mature basically, transfusion tissue, phloem and accessory transfusion tissue began to differentiate, so mesophyll tissue finally differentiated into developmental palisade cells and sponge cells. The thicker cuticle was formed in the lateral side of epidermal cells at the same time of differentiation and development for the inner structure of leaves. Therefore, the developmental palisade cells and the cuticle in the leaf structure of Podocarpus macrophyllus var. maki Endl. is greatly significant for photosynthesis and transpiration when it grows in arid and cold regions.