大葱雄性不育系及保持系花药和花粉发育的细胞学比较研究

为了从细胞学角度研究大葱雄性不育的机理,利用石蜡切片法对大葱雄性不育系及保持系花药与花粉发育过程进行比较研究。观察结果表明:大葱雄性不育系和保持系的小孢子母细胞都能正常进行减数分裂,四分体可以释放出小孢子。雄性不育系的花粉败育发生于单核小孢子时期,具有单核败育的特征。观察发现大葱雄性不育系的小孢子有2种败育类型:(1)绒毡层细胞正常发育,但中层细胞发生了延迟解体的现象,小孢子时期仍然存在,与逐渐缩小的药室一起挤压小孢子细胞成一染色极深的团块状物质;(2)绒毡层提前解体,不能提供小孢子发育所需的营养,小孢子的细胞质和细胞核逐渐解体,仅剩下内空的花粉粒。花粉败育不仅与绒毡层有关,还与中层细胞密切相关。

A cytological study on comparison of anther and pollen development in male-sterile and corresponding maintainer lines in Chinese onion

In order to investigate the mechanism of leek male sterility, a comparative study on anther and pollen development process in Chinese onion (Allium fistulosum L.) was carried out between the male sterile (MS) line and its corresponding maintainer (M) line by means of paraffin section. The result showed that the microspore mother cell of male sterile line could pass through meiosis and form tetrads and then tetrads could release microspore as the same as fertile line. The abortion of microspore occurred at the mono-nucleus microspore (MNM) stage,which had the characteristics of the MNM abortion. Two types of pollen abortion were observed in male sterile line by light microscope:(1)The tapetum could develop normally,but the middle layer still existed at MNM stage,the microspores were squeezed into a deep dyed conglomeration owning to the shrinking powder chamber;(2)The tapetum of male sterile line degenerated before fertile line,so as not to provide enough nutrition for microspore's development,the protoplast and nucleus of microspore degraded in succession and just left the empty pollen wall at last.