麻疯树小孢子发育的研究

用透射电镜观察了麻疯树(Jatropha curcas L.)小孢子发育的超微结构。小孢子母细胞时期内质网和质体较多;减数分裂和四分体时期,细胞处于明显的代谢活跃状态,细胞器丰富,主要有内质网、线粒体、质体、高尔基体和球状体;在小孢子发育早期和晚期,线粒体和内质网仍较丰富;小孢子经过高度的不对称分裂后,形成较大的营养细胞和较小的生殖细胞,营养细胞中细胞器数量明显减少,含大量的淀粉和脂类物质,生殖细胞中脂类物质丰富;表皮、药室内壁和中层细胞在小孢子母细胞和四分体时期淀粉粒丰富,小孢子时期明显减少,绒毡层从小孢子母细胞至小孢子发育晚期的细胞器都很丰富,主要为内质网、质体和线粒体,为二胞花粉发育奠定基础。

Ultrastructure of Microspore Development in Jatropha curcas L.

The ultrastructure of microspore development in Jatropha curcas L. was observed under transmission electron microscopy. Many endoplasmic reticulums and plastids are present at microsporocyte stage. Organells including endoplasmic reticulum, mitochondria, plastids, dictyosome and sphaeroplassts are rich in microspore at meiosis and tetrad stages. And mitochondria and endoplasmic reticulum are still abundant during early and late microspore stages. The microspore divides into a large vegetative cell and a small generative cell. The vegetative cell abounds with starch grains and the generative one is rich in lipids. A great number of starch grains occur in epidermis, endothecium and middle layers at microsporocyte and tetrad stages, and are remarkably reduced at microspore stage. The tapetum is rich in organells from microsporocyte stage till late microspore stage, mainly including endoplasmic reticulum, plastids and mitochondria. Starch grains and lipids supply nutrients for the pollen development.