甜椒胞质雄性不育雄配子发育的解剖学和超微结构研究

运用石蜡切片和电子显微镜超薄切片方法观察了甜椒(Capsicum annuum L．)细胞质雄性不育系8A和保持系8B雄配子发育过程。结果表明：不育系和保持系都能正常进行减数分裂,绒毡层细胞无明显差异,形成了正常的四分孢子。在四分体单核居中期后,不育系的绒毡层细胞异常膨大并伸进药室,挤压花粉粒,同时绒毡层细胞提前降解,不育系单核晚期花粉粒开始崩出内含物。致使不育系的雄配子在双核花粉粒形成之前就完全裂解,不能发育成正常的花粉粒。此外,超薄切片还观察到不育系花粉粒在单核早期绒毡层细胞线粒体空泡化,这种变化表明雄性不育的遗传缺陷包括在花药发育早期发生的线粒体结构变化。

Anatomy and Ultrastructure of Male Gametophyte Development in Cytoplasmic Male Sterile (CMS) Sweet Pepper (Capsicum annuum L.)

The male gametophyte development in a cytoplasmic male sterile (CMS) line 8A of sweet pepper (Capsicum annuum L.) and its maintainer line 8B were studied by optical and transmission electron microscope.The results showed that microsporogenesis could process normally and there was no difference in the tapetal cell between 8A and 8B lines before tetrad stage.Then, uninucleate pollen of 8A underwent a progressive process of rupture, owing to squeezing by abnormally swelled tapetal cells and to the premature degradation of tapetal cells.Male gametophytes in 8A ruptured before the first mitosis and became sterile.The results from ultrastructure observation revealed the presence of vacuolated mitochondrias in the tapetum of 8A.This suggests that the genetic defects in male-sterility include gross morphological changes in mitochondria and occur on the early stage of anther development.