大白菜CMS96不育系和保持系电镜观察

为了研究大白菜CMS96不育系花药败育机理,采用透射和扫描电镜,观察大白菜CMS96不育系和保持系的花药发育过程、花药和花粉表面结构。透射电镜结果表明,与保持系相比,在减数分裂期,大白菜CMS96不育系绒毡层与花药壁中层分开,不育系花粉母细胞皱缩,形状不规则,空隙较大,严重影响减数分裂正常进行;在单核小孢子时期,小孢子开始液泡化,直至成熟花粉期完全液泡化为空细胞,细胞壁严重萎缩,堆积在一起,最终花粉失去功能,导致败育。扫描电镜结果表明,大白菜CMS96不育系药室内的花粉畸形,花粉粒空瘪,表现为凹陷、扁平等形状,表面纹饰也呈多种不规则形状。花粉囊不开裂,没有花粉散出。初步认为,大白菜CMS96不育系花粉的败育从减数分裂开始到成熟花粉,伴随花粉发育整个过程。大白菜CMS96不育系药室内花粉粒虽具有花粉壁的结构,但扁平、空瘪,重叠堆积在药室壁上,失去了活力,无法散开。

Electron Microscopic Study on Male Sterile CMS96 and Maintainer Line in Chinese Cabbage

Using transmission and scanning electron microscopy techniques,anther and pollen development,surface of anther and pollen grains were studied in order to obtain differences between CMS96 and maintainer line in Chinese cabbage(Brassica campestris L.ssp.pekinensis).Results of transmission electron microscopy showed middle layer and tapetum of CMS96 were separated during meiosis.And early pollen mother cells(PMC) of CMS96 were with irregular shape and many larger gaps.Thus meiosis of PMC was influenced seriously.During mononuclear stage,microspore began to be vacuolated and mature pollens were empty to be seriously in cell wall and piled together leading to pollen grain abortion.Results of scanning electron microscopy showed pollen grains of CMS96 in the anther were abnormal and empty with hollow and flat shape.Pollen veins were irregular.No grains were released because pollen sac closed.Preliminary results showed pollen grains abortion of Chinese cabbage CMS96 began from meiosis to mature pollen along with the whole pollen development.CMS96 could form pollen grains with cell wall,but the compositions inner the pollen grains were empty.The abnormal pollen grains adhered to the inner anther without dispersing.