【摘要】 月季试管苗在生长过程中,能完整地观察到茎源不定根发生的全过程。当绿梢栽植试管后的数天内,基部尚处于初生分生组织时,在原形成层外围相当于初生韧皮部的若干点细胞开始脱分化为原分生组织——根原基细胞,由此分裂产生根尖分生区,因此月季试管苗不定根的发生属内生源。根尖分生区在未穿出幼茎皮层时,先端就开始有根冠的形成,当绿梢基部已发育为初生构造时,根尖已开始露白2mm,此时整个根尖已分化为:根冠,分生区,较短的伸长区和处于初步分化状态的成熟区,不定根的成熟区和幼茎交接部位的幼茎形成层衍生区,通过电镜制样,可观察到衍生区的细胞有内突的细胞壁,丰富的内质网,较多的线粒体等细胞器,发现此区存在着共质体运输的传递细胞群。更多还原

【Abstract】 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.更多还原