金线莲花药发育中多糖和脂滴的分布特征

Distribution Characteristics of Polysaccharides and Lipids in the Developing Anther of Anoectochilus roxburghii

该研究采用细胞化学方法研究了金线莲花药发育中多糖和脂滴的分布特征,以探索其花药发育中的物质代谢规律。结果显示:(1)在幼小花药中,花药壁的表皮和药室内壁以及造孢细胞中积累少量的淀粉粒。当小孢子母细胞形成胼胝质壁时,药壁细胞和小孢子母细胞中的淀粉粒减少并且出现一些脂滴,这一现象持续到二胞花粉;在二胞花粉中,糖类代谢显著增强;开花时,成熟花粉中积累了较多的淀粉粒和较少的脂滴。(2)金线莲花粉以花粉块形式发育,其特征为;①在造孢细胞时期一些特殊细胞壁就已确定了花粉块的界限;②在小孢子母细胞时期,胼胝质壁覆盖在整个花粉块表面,但内部花粉没有胼胝质壁结构;③二胞花粉后期,孢粉素花粉外壁覆盖在整个花粉块表面,但内部花粉没有外壁。金线莲花粉块发育的这些结构特征对植物花粉发育规律提出了多项疑问。

The distribution characteristics of polysaccharides and lipid droplets in the development anther of Anoectochilus roxburghii were studied by cytochemistry.The result shoued that:(1)in young anthers,a small amount of starch grains are accumulated in the epidermis and the endothecium of the anther wall and the sporogenous cells.When the microspore mother cell forms a callose wall,the starch grains in the cells of anther wall and microspore mother cells decrease,and some lipids appear in the microspore mother cells,which continue to the bicellular pollens.However,in the two-celled pollen,the sugar metabolism was significantly enhanced,and by the time of flowering,more starches and fewer lipids were accumulated in the mature pollens.(2)The A.roxburghii pollen develops in the form of pollinium.There are three developmental characteristics of the pollinium:①some special cell walls of sporogenous cells have been specialized and determined the outline of the pollinium.②During the microspore mother cell period,the callose wall covers on the surface of entire pollinium,not on internal pollen.③In anaphase of bicellular pollen,the sporopollenin exine covers on the surface of the whole pollinium,not on internal pollen grains.These structural features of the development in the form of pollinium of A.roxburghii are reported little,and some interesting questions about pollen development of higher plant have been raised.