朱顶红花粉萌发过程中营养细胞质的超微结构变化

Ultrastructural Changes of Vegetative Cells in Amaryllis Pollen during Its Germination

本文应用透射电镜对朱顶红成熟花粉水合、活化和萌发的动态过程中营养细胞质的结构和组成变化进行了观察。成熟花粉具质体、线粒体、内质网、高尔基体。微丝束以聚集体的形式存在。花粉活化后，细胞器的数目和结构发生显著变化：质体和线粒体的片层明显增加，内质网片层狭窄，高尔基体活跃产生小泡，脂体降解及微丝聚集体散开。花粉萌发后，细胞质中出现周质微管和被刺小泡，此期细胞器的变化不明显。微丝以纤丝状遍布整个花粉管中。

Structural and organizational changes of the vegetative cell in Amaryllis vittata Ait. during such dynamic processes of pollen as hydration, activation and germination have been examined with electron microscopy. The mature pollen grain is composed of such organelles as plastids, mitochondria,endoplasmic reticulum, dictyosomes and lipid bodies which are in their resting state. Microfilaments appear as aggregates. After pollen activation, however,the organelles undergo great changes in number and shape: the lamellae of plastids and the cristae of mitochondria increase conspicuously in number, the cisternae of the endoplasmic reticulum become narrower; the dictyosomes produce vesicles actively the lipid bodies become degraded and the microfilament aggregates disperse. Cortical microtubules and spiny vesicles appear in the cytoplasm after germination of the pollen tube. No apparent structural changes of the organelles were noticed any longer during this period and microfilaments are distributed throughout the entire pollen tube as a three-dimensional network.