苞叶姜大小孢子发生和雌雄配子体发育

对苞叶姜(Pyrgophyllum yunnanense)大小孢子发生和雌雄配子体发育进行了显微观察, 研究结果表明: 苞叶姜花药2室, 药壁发育属基本型, 绒毡层为分泌型。小孢子母细胞经减数分裂形成左右对称型四分体, 胞质分裂为连续型, 成熟花粉粒为2-细胞型; 子房下位, 3室, 胚珠多数, 倒生, 具双珠被、厚珠心, 中轴胎座。大孢子母细胞经减数分裂形成线型(或T形)四分体, 珠孔端3个大孢子退化, 合点端的1个发育成功能大孢子, 胚囊发育为蓼型。比较苞叶姜、黄花大苞姜(Caulokaempferia coenobialis)和海南三七(Kaempferia rotunda)的早期胚胎学特征, 表明苞叶姜与黄花大苞姜系统学关系较近, 与海南三七系统学关系较远。在分类等级上, 胚胎学证据支持苞叶姜独立成属。

Sporogenesis and Gametogenesis of Pyrgophyllum yunnanense (Zingiberaceae)

We report on the microsporogenesis, megasporogenesis and development of female and male gametophytes of Pyrgophyllum yunnanense. Anthers are 2-sporangiate, and the development of anther walls are classified as basic. The tapetum is glandular. The microspore mother cells give rise to isobilateral tetrads by meiosis. Cytokinesis is successive. The mature pollen grains are 2-celled and are shed singly. The ovary is hypostasy and trilocular. The species shows axial placenta with most ovules. The ovule is anatropous, bitegmic and crassinucellate. The chalazal megaspore in a linear or T-shaped tetrad becomes functional. The development of the embryo sac is polygonum. We performed comparative studies with the closely related species Kaempferia rotunda and Caulokaempferia coenobialis. P. yunnanense is closely related to C. coenobialis and is more distant with K. rotunda. P. yunnanense should be treated as an independent genus.