樱桃番茄叶体细胞胚发生的组织细胞学观察

Histocytological observation on somatic embryogenesis derived from leaves of cherry tomato

以樱桃番茄无菌苗叶片为外植体,在附加2.0 mg/L 6-BA+0.1 mg/L IAA的MS培养基上诱导培养,利用石蜡切片和透射电镜技术观察外植体体细胞胚发生过程中显微结构和超微结构的变化。显微观察结果表明,培养5天后,部分叶肉细胞通过脱分化而进入分裂,开始形成胚性细胞;13天后切口处可诱导出淡黄色胚性愈伤组织,继续培养可产生体细胞胚。体细胞胚发生不同步,经历球形胚、心形胚、鱼雷胚,子叶胚等阶段,同时有畸形胚的出现。胚根进一步发育的过程中,伴有次生胚的出现。超微结构观察表明,樱桃番茄叶片离体体细胞胚发生过程中细胞质、细胞核、细胞壁、线粒体、高尔基体和叶绿体等细胞结构均发生规律性的变化。

The leaves of cherry tomato（Lycopersivon esculentum Mill.） as explants were cultured on MS medium added with 6-BA 2.0 mg·L-1 and IAA 0.1 mg·L-1 to form embryogenetic callus.The microstructure and ultrastructure of the explants were observed by paraffin sections and transmission electron microscopy during somatic embryogenesis.The results showed that some of the mesophyll cells went into dividing through dedifferentiation and started to form embryonic cells at the cultured 5th day.The incision could be induced as light yellow embryogenic callus after 13 days and could continue to produce somatic embryos.Somatic embryogenesis was not synchronized,and went through globular stage,heart-shaped stage,torpedo stage and cotyledon stage,and at the same time had the appearance of abnormal embryos.The emergence of secondary embryos accompanied by the radicle further development.Ultrastructural observation showed that the cytoplasm,nucleus,cell wall,mitochondria,Golgi bodies,chloroplast and other structures in embryonic cells of cherry tomato explants changed regularly during in vitro somatic embryogenesis.