条斑紫菜壳孢子超微结构研究

Study on ultrastructure of conchospore of Porphyra yezoensis

应用戊二醛、锇酸固定,环氧树脂包埋,醋酸双氧铀-柠檬酸铅制作切片,以透射电镜观察条斑紫菜(Porphyra yezoensis)壳孢子的超微结构,结果表明:壳孢子外包被一层薄的细胞壁,中央为一个由同心片层结构的类囊体膜构成的轴生星状色素体,色素体中有一个无淀粉鞘包被的蛋白核,类囊体膜上附有嗜锇性的质体小球。壳孢子细胞核位于色素体的一侧,呈不规则的长圆形,核仁偏于核的一侧。在胞质中分布有线粒体、红藻淀粉、液泡等细胞器。与放散前的成熟壳孢子囊枝细胞超微结构比较,成熟壳孢子超微结构的变化主要有细胞壁变薄,色素体结构松散甚至退化,蛋白核分裂,液泡数量增多而红藻淀粉数量减少等,这些变化反映了成熟壳孢子基本细胞特征,同时反映了在壳孢子生长发育过程中温度下降、光照时间缩短和光照强度减弱等环境因素的变化。

With observation of transmission electron microscope, ultrastructure of conchospore of Porphyra yezoensis was studied, it was shown that thin cell wall appeared outside of conchospore, while in the center of it, a star-shaped chromatophore thylakoid existed. There is no starch sheath pyrenoid embedded in chromatophore. Lipid bodies stained with osmium could be observed on the membrane of thylakoid. A round- like nucleus located in the chromatophore with deeper darkness. There are other cellular organs observed such as floridean starch, mitochondria, vacuole and so on. Besides, this study indicated that mature conchosporangial cell phase was important for conchospore release and influenced by environmental factors like temperature, length and intensity of sunlight.