紫萼花粉粒和花粉管中微丝的超微结构

用常规化学固定和化学固定前用鬼笔环肽处理两种电镜样品制作技术,分别研究了紫萼Hosta venteicosa (=H.coerulea]成熟花粉粒和幼花粉管中的微丝的超微结构。结果表明,在常规电镜固定中花粉粒中的微丝能保存,但在花粉管中的则遭受破坏。用鬼笔环肽处理后化学固定的方法,微丝在花粉管中能良好地保存。在花粉粒中平行的微丝形成束,表现为具分布的特点,即限于分布在它们功能的区域,并且微丝束经常紧密地与营养核贴近。在幼花粉管中微丝束表现为在线粒体、质体、内质网、小泡和小液泡的表面通过,并常常与脂体紧密联结。这些现象表明在花粉萌发和花粉管生长时,微丝与营养核及与其它细胞器的运动之间存在某些联系的迹象。

ULTRASTRUCTURE OF MICROFILAMENTS IN POLLEN AND POLLEN TUBES OF HOSTA VENTRICOSA(=H.COERULEA)

Ultrastructure of microfilaments in pollen grains and pollen tubes of Hosta ventricosa (=H.coerulea) was investigated.Results indicate that microfilaments with conventional chemi- cal fixation are preserved only in pollen grains,but destroyed in pollen tubes.Microfilaments treated with phalloidin before chemical fixation are found preserved in pollen tubes.In pollen grains a pronounced organization of parallel microfilaments appeared in bundles with its distri- bution characteristics is always restricted to their functional domains where bundles were in close contact with the vegetative nucleus.In young pollen tubes cytoplasmic bundles of micro- filaments appeared also to pass close to the surface of mitochondria,plastids,endoplasmic re- ticulum,vesicles and small vacuoles,and always associated with lipid bodies.These findings strongly indicate that there is a relationship between microfilaments and the movement of vege- tative nucleus and other organelles in the germination of pollen grains and in the growth of pollen tubes.