凤仙花花药发育中多糖和脂滴组织化学研究

以不同发育时期的凤仙花花药为实验材料,采用组织化学方法,对花药发育中的结构变化及多糖和脂滴物质分布进行观察。结果表明:(1)凤仙花的花药壁由6层细胞组成,包括1层表皮细胞,2层药室内壁细胞,2层中层细胞和1层绒毡层细胞。其中绒毡层细胞的形态不明显,很难与造孢细胞区分,且在小孢子母细胞时期退化。(2)在小孢子母细胞中出现了一些淀粉粒,但减数分裂后,早期小孢子中的淀粉粒消失,又出现了一些小的脂滴;随着花粉的发育,小孢子形成大液泡,晚期小孢子中的脂滴也消失;小孢子分裂形成二胞花粉后,营养细胞中的大液泡降解、消失,二胞花粉中又开始积累淀粉;接近开花时,成熟花粉中充满细胞质,其中包含了较多的淀粉粒和脂滴。(3)在凤仙花的花药发育中,绒毡层细胞很早退化,为小孢子母细胞和四分体小孢子提供了营养物质;其后的中层细胞退化则为后期花粉发育提供了营养物质。

Histochemical Study of Polysaccharides and Lipids on the Developing Anthers of Impatiens balsamina

The anther development of Impatiens balsamina displays some special characters:(1)Anther wall consists of 6 layers of cells:one epidermis,two endotheciums,two middle layers and one tapedum.Tapetal cells are not clear during sporogenous stage and difficult to distinguish with sporogenous cells.The tapetal cells degenerate during the stage of microspore mother cell (MMC).(2)Some starch polysaccharides appear in the microspore mother cells which had formed a callose wall.After meiosis of MMCs,starches in early microspores disappear,and lipids were accumulated in early microspores.With microspore developing,late microspores formed several large vacuoles and lipids disappeared.After microspore division,comparing with the big vacuoles in vegetative cell disappearing,starches again appeared in the 2-cellular pollen.Nearly anthesis,mature pollen grains of I.balsamina accumulated many lipids and starches as storey materials.(3)During anther development of I.balsamina,some cells of anther wall degenerated and their cytoplasm transformed lipids for pollen absorbing,the tapetal cells degenerated and offered lipids for MMCs and microspores,and middle layer cells for bicellular pollen grains.