Keijzer C J
Department of Plant Cytology and Morphology, Agricultural University, 6703 BD Wageningen, The Netherlands.
New Phytol. 1987 Mar;105(3):499-507. doi: 10.1111/j.1469-8137.1987.tb00887.x.
The development of the locule of Gasteria verrucosa (Mill.) H. Duval and Lilium hybrida cv. Enchantment, especially the border between the sporophyte and the gametophyte, is investigated by means of light and electron microscopy, histochemistry and micromanipulation and related to pollen dispersal. The pecto-cellulosic cell walls of both the middle layer and the tapetum and a part of the endothecium disappear, and the tapetum cells are covered with sporopollenin-containing tapetal membranes and orbicules. The cell contents of the tapetum turn into the hydrophobic pollenkitt. In the locule, similar changes are observed as the pecto-cellulosic and callose walls of the meiocytes disappear and the future pollen grains are covered with the sporopollenin-containing exine. Due to their non-wettability, these hydrophobic substances on both sides of the sporophyte-gametophyte surface are important in pollen dispersal. The transfer of pollenkitt from the tapetum to the locule appears to be due to capillary forces in the locule after the continuous expansion of the pollen, rather than to active flow or to direct attraction by the pollen grains.
采用光学显微镜和电子显微镜、组织化学及显微操作技术,对琉璃殿(Gasteria verrucosa (Mill.) H. Duval)和百合杂交种“魅惑”(Lilium hybrida cv. Enchantment)的子房发育,尤其是孢子体与配子体之间的边界进行了研究,并将其与花粉传播相关联。中层和绒毡层以及部分药室内壁的果胶 - 纤维素细胞壁消失,绒毡层细胞被含孢粉素的绒毡层膜和球状体覆盖。绒毡层的细胞内含物转变为疏水性的花粉外壁蛋白。在子房中,也观察到类似的变化,即减数分裂细胞的果胶 - 纤维素壁和胼胝质壁消失,未来的花粉粒被含孢粉素的外壁覆盖。由于它们的疏水性,孢子体 - 配子体表面两侧的这些疏水物质在花粉传播中起着重要作用。花粉外壁蛋白从绒毡层转移到子房似乎是由于花粉持续膨胀后子房中产生的毛细作用力,而不是由于主动流动或花粉粒的直接吸引。