北沙参根的发育解剖研究

ANATOMY STUDIES ON THE DEVELOPMENT OF ROOT OF GLEHNIA LITTERALIS

北沙参根的初生构造中，初生木质部为二原型，皮层薄壁细胞占主要地位；次生构造中由维管形成层产生的次生维管组织占主导地位。其中以薄壁细胞为主，维管分子少量，分散在薄壁组织中；分泌道少量，分散在次生韧皮部和韧皮射线中，属次生泌道，初生构造中无分泌道存在。木栓形成层发生较早，由中柱鞘细胞中产生，一年生北沙参根木栓形成层只发生一次。

rimary xylem belongs to diarch and parenchyma cell in cortex is dominant in primary structure of root of Glehnia litteralis. Secondary vascular tissue, which derives from vascular cambium, dominates the secondary structure. Parenchyma cell is prominent in the secondary vascular tissue, and only small amount of vascular element is scattered in it. Secretory canal which belongs to secondary secretory canal is scattered in secondary phloem and phloem ray. There is no secretory canal exists in primary structure. Phellogen earlier derives from pericycle once time in the root of therophyte of Glehnia litteralis.