月季试管苗不定根发生的组织学和细胞学研究

CYTOHISTOLOGICAL STUDIES ON THE ADVENTITIOUS ROOT OF THE TISSUE CULTURE SHOOT OF ROSA CHINENSIS JACQ

The primordium cell group of the adventitious root of the tissue culture shoot on RosaChinensis Jacq, origins from the exothecium of the procambium. It conforms to theendotrophic. The continual mitosis of the primordium cell forms the root apex meristemzone and the continual growth of the meristem forms the root tip. When the root tip per-forates the cortex of the young stem, it has four zones-the root cap, meristem zone,elongation zone and maturation zone. The vessel, sieve tube, sieve plate and companioncell are seen from ultrastructure of the stele. The thin cell wall, the protoplasm which be-comes limited to the parietal region, and the protoplasm bridge which divides the vaculecan be seen on the ultrastructure of the cortex in the adventitious root. The inprojection ofthe cell wall and the full endoplasm reticulum and many mitochondra are seen in theultrastructure of the derivative zone of the cambium of the young stem connecting withthe maturation zone of the adventitious root. That is the transfer cell. The callus arisesfrom the exothecium cell of cortex in the young stem and it has no histological connectionwith the adventitious root.