濒危植物香木莲的胚胎学研究

A Study on the Embryology of Endangered Plant Manglietia aromatica

对香木莲 (Manglietia aromatica)的大、小孢子发生以及雌、雄配子体发育过程进行了研究 ,并结合已有的资料归纳出木莲属的胚胎学特征。香木莲花药四囊型 ,腺质绒毡层有 1～ 2层细胞 ,小孢子形成时胞质分裂方式为修饰性同时型 ,小孢子四分体排列方式为交叉型 ,有时为左右对型 ,成熟花粉粒为二细胞型。胚珠倒生 ,厚珠心 ,双珠被 ,大孢子四分体呈直线排列 ,功能大孢子位于合点端。胚囊发育属于蓼型。木莲属的胚胎学特征与木兰属、含笑属、鹅掌楸属等植物的胚胎学特征基本相同 ,都属于较原始的被子植物胚胎类型。

This paper deals with the microsporogenesis,megasporogenesis,development of the male gametophyte and female gametophyte of Manglietia aromatica.The anther of Manglietia aromatica is tetrasporangiate with glandular tapetum,which consists of one or two layers of cells.Cytokinesis during meiosis of its microspore mother cell is modified simultaneous type,and tetrads are decussate,or isobilateral sometimes.Mature pollen grains are 2-celled.Tetrad cells and microspores are irregularly shaped during the microsporogensis.The ovule is anatropous,bitegmic and crassinucellate.The outgrowth of its funicle develops into obturator.The megaspore mother cells undergo meiotic divisions and develop into a linear tetradas of megaspores.The chalazal megaspore are functional one,which develops into a Polygonum type of embryo sac.The embryological characteristics of Manglietia aromatica are very similar to those of Magnolia,Michelia and Liriodendron in Magnoliaceae.