白穗花有性器官与胚胎发育形态的研究

Studies on Sexual Organs and Embryological Development Morphology of Speirantha gardenii(Convallariaceae)

利用石蜡切片技术对白穗花(Speirantha gardenii(Hook.)Baill.)胚胎发育过程进行了显微观察。研究结果表明:白穗花具四室花药,腺质绒毡层;小孢子母细胞减数分裂为连续型,四分体主要为左右对称型,偶有直线型、T型和交互对生型;成熟花粉为二细胞型;子房三室,中轴胎座;倒生胚珠,双珠被,厚珠心型,珠孔由内珠被形成;胚囊的发育为蓼型;胚的发育类型为柳叶菜型,核型胚乳。根据已有的胚胎学资料,比较白穗花和铃兰族(Convallarieae)其它植物的胚胎学特征,结果显示:(1)白穗花属(Speirantha Baker)与蜘蛛抱蛋属(Aspidistra Ker-Gawler)的胚胎学特征更为接近,二者可能起源于共同的祖先;(2)夏须草属(Theropogon Maxim.)是铃兰族的异质类群。

We investigated the embryological characters of Speirantha gardenii （Hook.） Baill.（Convallariaceae）. The anther has 4 sporangiates and a glandular tapetum. Meiosis of the microspore mother cells was accompanied by successive cytokinesis, for the formation of mostly an isobilateral tetrad. Occasionally linear, T-shaped and decussate microspore tetrads were observed. The mature pollen grains were 2 celled. The ovary was trilocular with axile placentation and anatropous, biteguminous and crassinucellate ovules. The micropyle was formed by the inner integument. The development of the embryo sac conformed to the Polygonum type. The embryogeny belongs to the Onagrad type, and endosperm development as the nuclear type. Comparison with other studied species in Convallarieae revealed that （1） Speirantha and Aspidistra may have a common ancestor and （2） Theropogon may be an alien in the tribe.