摘要
蕨类植物成熟卵的周围有一层卵膜,但其细微结构和形成过程仍不清楚,本研究应用透射电镜技术对水蕨(Ceratopteris thalictroides)卵细胞发育过程中卵膜的形成及超微结构进行了观察。结果表明水蕨卵细胞在发育中期开始形成卵膜,卵上方的卵膜十分显著,是由多层嗜锇性内质网片层附着于质膜内表面形成的,成熟时卵上方的卵膜中心部分厚,向边缘逐渐变薄,在嗜锇性片层之间填充有嗜锇性物质。比较而言,卵下方及侧面的卵膜薄,由两层紧密连接的嗜锇性膜构成。首次阐明了蕨类植物卵膜形成的超微结构,并对卵膜的一些功能进行了探讨。
The mature egg of ferns possesses a layer of egg membrane in the periphery. However, the fine trastructure and the formation of the egg membrane in the egg of ferns are still unclear. The present paper described the formation and the ultrastructure of the egg membrane in the egg of the fern Ceratopteris thalictroides using transmission electron microscopy （TEM）. The results show that the egg membrane begins to form at the stage of the maturing egg. The egg membrane in the upper side of the egg is prominent. It is formed by attaching of osmiophilic sheets of endoplasmic retieulum to the inner surface of the plasmalemma. When mature the egg membrane in the upper side of the egg is much thick in the central region and it becomes thinner gradually towards the margin. Some osmiophilie materials are filled in the spaces between the sheets of endoplasmic retieulum. On the contrary, the egg membrane in the lower side of the egg is thin. It is composed of two osmiophilic membranes which are associated with each other closely. The formation and the ultrastructure of the egg membrane are described for the first time. Some functions of the egg membrane are also discussed.
出处
《云南植物研究》
CSCD
北大核心
2008年第5期543-548,共6页
Acta Botanica Yunnanica
基金
The National Natural Science Foundation of China(30670128)
关键词
蕨
水蕨
卵膜
超微结构
Fern
Ceratopteris thalictroides
Egg membrane
Uhrastructure
