利用透射电镜技术对栽培甜菜(Beta vulgaris)花粉发育过程进行了超微结构观察。结果表明, 在小孢子母细胞减数分裂期间, 细胞内发生了“细胞质改组”, 主要表现在核糖体减少, 质体和线粒体结构发生了规律性变化。末期I 不形成细胞板,而是在2个子核间形成“细胞器带”。“细胞器带”的存在起到类似细胞板的作用, 暂时将细胞质分隔成两部分。四分体呈四面体型, 被胼胝质壁包围。小孢子外壁的沉积始于四分体晚期, 至小孢子晚期外壁已基本发育完全。单核小孢子时期, 细胞核大, 细胞器丰富。二细胞花粉发育主要表现在生殖细胞壁的变化上, 生殖细胞壁上不具有胞间连丝。成熟花粉为三细胞型, 含有1个营养细胞和2个精细胞。精细胞具有短尾突, 无壁, 为裸细胞, 每个精细胞通过2层质膜与营养细胞的细胞质分开。生殖细胞与精细胞里缺乏质体。

The ultrastructure of pollen development in Beta vulgaris was investigated by transmission electron microscopy. Cytoplasm reorganization occurred during meiosis of microsporocytes and resulted in decreased ribosomes and regular changes of plastids and mitochondria. Telophase shows an organelle band between two nuclei. The function of the organelle band is similar to that of the cell plate that separates the cytoplasm into two parts. The tetrasporophyte wrapped by callose is of simultaneous type. Depositions of wall started at the late tetrad stage, and the exine was fundamentally completed by the late microspore stage. The monokaryotic microspore has a large nucleus and abundant organelles. Development of 2-celled pollen is accompanied by changes in the generative cell wall, which showed no plasmodesmata. Mature trinucleate pollen grains showed a vegetative cell and two sperm cells, each sperm cell separated from the vegetative cytoplasm by two continuous membranes that enclosed the cytoplasm and nucleus. Sperm was a naked cell and had a short caudal. Generative cell and sperm showed no plastids.