【摘要】 以虎眼万年青(Ornithogalum caudatum Jacq.)子鳞茎的鳞叶为外植体,不经过愈伤组织阶段,直接诱导体细胞胚胎发生并再生植株。组织切片和扫描电镜的观察结果表明:体细胞胚来自鳞叶表皮最外层的单个细胞。这个细胞经第一次平周分裂,成为2-细胞原胚,然后依次经过4-细胞原胚、球形胚、香蕉形胚等阶段发育成小植株,其形态学发育过程与合子胚相似。小植株移入土中,1周后即可成活。此外,还观察到直接体细胞胚只产生于鳞叶的近轴面,而远轴面无体细胞胚产生,这两个部位在细胞结构和形态上有显著差异。更多还原

【Abstract】 Direct somatic embryos were formed on the explants of Ornithogalum caudatum Jacq. that were excised from the bud scales of the small bulls when placed on an appropriate culture medium . Histological and scanning electron microscopic examinations showed that somatic embryogenesis was initiated from single cells of the outermost layer of the epidermis. The embryogenic cell underwent a periclinal division giving rise to a 2-celled proembryo which developed into the mature embryo through different morphological stages similar to that of a zygotic embryo. The somatic embryos germinated into plantlets which were then transplanted into soil. It was noted that the somatic embryos were formed exclusively on the adaxial surface of the bud scale rings while no embryos were observed on the abaxial surface of the rings. A distinctive difference in cell structure and morphology between these two parts of the explants was observed.更多还原