朱顶红成熟花粉萌发过程中生殖细胞微管变化的超微结构观察

应用透射电镜对朱顶红花粉水合、活化和萌发过程中的超微结构尤其是生殖细胞微管的结构形式和分布格局的变化进行了详细的观察.在成熟花粉时期,椭圆形生殖细胞中的微管组成纵向束平行于细胞的长轴分布并靠近质膜,微管间无结构上的联系.花粉活化时,生殖细胞形状不断变化,微管的数量显著减少,多为单一微管具各种方向分布.花粉萌发后,进入花粉管中的生殖细胞为纺锤状,具多个裂瓣,微管的结构形式和分布方式与成熟花粉时期的相似,即微管组成纵向束,充满裂瓣.但微管间及微管与质膜间以横桥相互连接.

Ultrastructural Changes of Microtubules in Generative Cells of Amaryllis Pollen During Its Germination

Organizational changes of microtubules (Mts) in the generative cell (GO of Amaryllis vittata Ait. have been observed in mature pollen grain until GC entering into pollen tube using electron microscopy. In mature pollen grain, the GC was ellipse-shaped, Mts were organized as bundles and distributed in the proximity of the GC plasma membrane. During pollen activation, the GC varied in shape. The amount of the Mts greatly decreased. The Mts were singles with various orientations. Following migration into the pollen tube, the GC was spindle-shaped with many lobes. The Mts organization and distribution were similar to that in mature pollen grain, i. e. , Mts arranged in longitudinal bundles and filled the GC lobes. But the Mts were cross-linked with arms.