百合类体细胞胚和体细胞胚的形态学与组织学研究

 以东方百合‘Siberia’的无菌苗叶柄为试材，诱导产生初始分生结节组织。其后对分生结节组织进行分化再生采用体式显微镜观察和石蜡切片分析的方法对诱导得到的类体细胞胚和体细胞胚再生结构进行形态学和组织学观察。百合类体细胞胚结构呈球形至心形结构或芽状，组织内部主要由薄壁细胞组成，与母体组织存在着明显的维管组织联系，具有多个维管组织中心，其外形与体细胞胚极为相似。百合体细胞胚发源于分生结节表面新生的胚性愈伤组织，经历球形、椭圆形和子叶形胚阶段发育形成完整的植株，在整个发育过程中与母体愈伤组织在整个发育过程中无维管组织联系，且它的根芽两极同时发生，相互联系。研究结果表明，两种再生结构虽然具有极相似的外观形态，但是在发育方式和内部组织结构上截然不同。

Morpho-histological Study of Somatic Embryo-like Structures and Somatic Embryos in Lily

Petioles of lily were used as explants to induce primary nodular callus. Then，somatic embryo-like structures were induced from the primary nodular callus and somatic embryos were induced from the proliferated nodular callus，a systematic morpho-histological study was conducted for showing the differences of the two regenerated structures by microscope observation and paraffin section analysis. The somatic embryo-like structures were globular to oval-shaped or similar to shoots，and consisted of parenchymatous cells. Histological observations indicated their connection with the maternal tissue by evident vascular strands and the existence of multiple vascular centers during morphogenesis. These structures closely resembled somatic embryos in appearance. Somatic embryos derived from the newly embryonic callus situated at the surface of the proliferated nodular callus，and the early-stage somaticembryos were formed by embryonic cells. Somatic embryo grew into a complete plantlet after passing through globular，oval and cotyledonary-shaped stages. Histological observations did not reveal any vascular connections with the maternal tissue during the whole development process. Moreover，the shoot pole and root pole of them appeared simultaneously，their connection was built up through a single vascular bundle. Therefore，even much similar appearance between the two regenerated structures，their development manners and organizational structures totally differ.