【作者】 陈小军；

【导师】 丁毅；

【作者基本信息】 武汉大学 ， 遗传学， 2004， 硕士

【摘要】 本文以云南紫稻无花粉型细胞质雄性不育系（Oryza sativa L.）为材料,采用常规石蜡切片光镜观察和超薄切片电镜观察方法,对不同发育时期的紫稻不育系和保持系花药进行了败育的形态学观察、可育与不育花药中Ca²⁺分布的比较观察,主要实验结果如下: 1.花药石蜡切片的观察:采用常规石蜡切片的固定、包埋方法,对不同发育时期的不育系和保持系花药进行光镜观察的结果表明,紫稻保持系花药发育正常,不育系花药发育异常,出现药室合并、绒毡层细胞延迟退化等现象。紫稻不育系败育主要发生在减数分裂期,只有少数在小孢子时期发生败育,属于无花粉型雄性不育败育途径。 2.超薄切片观察花药Ca²⁺分布:运用焦锑酸钾沉淀法研究了不育系和保持系花药在发育过程中小孢子及绒毡层细胞Ca²⁺分布的结果表明,在花粉发育过程中,保持系的花粉胞质内部基本无Ca²⁺的沉淀,后期花粉外壁出现Ca²⁺的沉淀。保持系早期绒毡层细胞形态正常,胞内有少量Ca²⁺沉淀。后期绒毡层细胞开始凋亡,胞质凝集,胞内出现大量Ca²⁺的颗粒;不育系花粉在发育的早期败育,胞质液泡化,内部出现大量Ca²⁺的沉淀。不育系绒毡层细胞形态正常,没有出现退化现象,胞内无Ca²⁺的沉淀。值得注意的是,我们发现在不育系花药中绒毡层和小孢子之间出现大量Ca²⁺颗粒,在某些时期还形成一个含Ca²⁺极为丰富的“Ca²⁺区带”。这种现象在以前尚未有过类似报道。通过对保持系和不育系花药在不同发育时期的Ca²⁺分布的比较观察,我们认为不育系花药绒毡层细胞与小孢子中这种Ca²⁺的异常积累可能与雄性不育相关。更多还原

【Abstract】 The paraffin section and ultracytochemical methods were employed to investigate the morphological character and the changes of calcium distribution in fertile and sterile anthers of a new cytoplasmic male sterile (CMS) purple rice (Oryza sativa L.) during the anther development. 1. Paraffin section observation: Normal paraffin section fixation and embedding method was used to observe the morphological difference between anthers of the cytoplasmic male sterile rice and its maintainer line. The fertile anthers had a natural morphology, while aberrant forms were found in sterile anthers such as fusion of pollen cell,degeneration delay of tapetal cells; At most of the time, the pollen of sterile line aborted at miosis stage, which means this kind of rice belongs to the Non- polleniferous male sterile rice type.2. During the development of the microspore and tapetum, potassium antimonite was used to locate Ca~2+ in fertile and sterile anthers of purple rice. In the fertile anthers, there were abundant Ca~2+ precipitates on the surface of early microspore, but not in the cytoplasm. In the tapetum, there were little calcium precipitates in the normal cytoplasm in the early stage; in the later stage, the tapetum cells underwent programmed cell death and a great quantity of calcium precipitated. In the sterile anthers, the microspore aborted at the early stage and abundant calcium precipitated in the vacuolated cytoplasm. There were abundant Ca~2+ precipitates between the tapetum and microspore, but not in the tapetum cells. The results indicate that abnormalities in the distribution of calcium between the tapetum and microspore correlate with cytoplasmic male sterility.更多还原