秦艽的胚胎学研究

秦艽具５个雄蕊，花药壁的发育属于双子叶型，为变形绒毡尾，花粉母细胞减粉分裂时的胞质分裂为同时型，四分孢子主要呈四面体型，成熟花粉粒球形，具３－孔沟，多为２细胞。子房一定，中轴胎座，其上着生众多具单珠被，薄珠心的倒生胚珠，大孢子母细胞减数分裂形成线型四分体。合点端大孢子继续发育，少数为合点端第二个大孢子形成功能大孢子，胚囊发育属蓼型，受精作用属于有丝分裂前配子融合类型，胚按茄型发育，胚乳核型，胚乳早

EMBRYOLOGICAL STUDIES IN GENTIANA MACROPHYLLA

A flower in Gentiana macrophylla has 5 stamens,the deveopment of anther walls conformsto the dicotyledonous type. Tapetum is of plasmodial type and some cells become two-layered atthe later period. Cytokinesis in the microsporocyte meiosis is simultaneous type and microspore te-trads are mainly tetrahedral.Pollen grains are 2-celled,global shape with three grooves. The ovule is anatropous,unitegmic and tenuinucellate.A monocellular archesporium devel-ops into megasporocyte directly. The megasporocyte undergoes meiosis and forms a linear tetrad.Most of the functional megaspores which develop into Polygonum type embryo sac come from thechalazal megaspore,only a few are from the second megaspore of the chalazal end. The fertiliza-tion belongs to the premitotic type of syngamy.Embryogeny conforms to the Solanad type,en-dosperm formation is of Nuclear type ,Cell wall of early endosprem cell is from the free growthwalls which are near the embryo sac wall.