萝卜花蕾败育过程中的组织细胞学特征观察

Observation of Histocytological Feature on Radish Flower Bud during Aborting

为了解萝卜花蕾在生长发育过程中发生败育现象的机理,选用萝卜正常花蕾和败育花蕾进行了DNA水平和细胞形态学上的比较分析。结果表明,在DNA水平上,败育花蕾表现出明显的DNA Ladder现象,而正常花蕾的DNA表现完整,说明败育花蕾具有细胞程序化死亡特征;在光镜下观察到:败育花蕾的萼片、花瓣和花药组织都发生了明显的退化,表现为下表皮退化和组织中层薄壁细胞层数减少;在电镜下观察到:萼片组织的细胞内细胞器发生退化,表现为线粒体内的嵴数目减少、双层膜破坏;细胞核畸形、核膜破裂;叶绿体内的基粒和基质片层结构破坏,或叶绿体解体。

To investigate the mechanism of abortion on the flower bud of radish,the normal and aborting flower bud were taken and compared on DNA level and histocytological level by light and electron microscope.It were found that the DNA ladder obviously appears in the abortion flower bud,but the normal DNA was in the complete-grown flower bud on the molecular level,which means that the abortion of flower bud have the similar feature as PCD,From the optical microscope,it was found that the tissue of petal,anther and sepal in aborted flower had degenerated obviously,especially parenchyma cell and lower epidermis disappeared,From the electronic microscope,it was found that the organelle in the sepal cell of aborted flower bud had degraded,such as a fewer ridge cristae in mitochondria or the double-layer membrane broken,malformation nuclei or membrane broken,the structure of grana and stroma lamellae of chloroplast were disrupted also.