黄芩（Scutellaria Baicalensis Georgi）的胚胎学研究

本文运用常规石蜡制片方法,对黄苓(Scutellaria baicalensisGeorgi)的胚胎学进行了较为系统的研究。其主要结果如下:1,雄蕊—4,2强。前对花药较长,是四个小孢子囊;后对花药较短,具两个小孢子囊。幼嫩花药横切可见,表皮下具一个或多个孢原。花药壁由四层细胞组成,由外向内为表皮、药室内壁、中层、绒毡层,其发育方式为双子叶型。绒毡层细胞部分来源于初生壁细胞,部分来源于药隔的基本组织。绒毡层细胞最初为单核,后分裂为双核。分泌型绒毡层。小孢子母细胞是由次生造孢细胞分裂后发育而来的。其减数分裂中的胞质分裂为同时型,四分体的排列主要为四面体型,也有交叉型。成熟花粉粒为2—细胞型。2,子房二心皮、四室、每室一个胚珠,中轴胎座,单珠被,薄珠心,倒生型胚珠。孢原细胞一个,孢原细胞直接发育形成大胞子母细胞,后者经减数分裂形成的线形排列的四个大孢子中,有功能的大胞子的数目及其位置不确定。胚囊发育为蓼型。助细胞具钩状器结构。极核在受精前融合为次生核。反助细胞在受精前开始退化。3,胚发育属柳叶菜型。其发育历经原胚期、心形胚期、鱼雷胚期至成熟胚期。胚柄在球胚早期达到最高度发育,鱼雷胚晚期开始退化。胚柄很长,球胚早期,胚柄已将胚经狭窄的胚囊中部推入到宽大的合点区。胚乳发育为细胞型。

EMBRYOLOGICAL STUDIES IN SCUTELLARIA BAICALENSiS GEORGI

This paper studies the embryology of Scutellaria baicalensis Georgi.It is composed of magmegasporgensis and microsporogenesis;development of female and male gametophyte;and development of embryo and endosperm.The main results are as follows: 1 The anther wall comprises four layers,its development follows the dicotyledonous type.The tapetum is partly originated from the primary parietallayer and partly derived from the ground tissues of the connective. Tapetum with dinucleate cell belongs to secretory type.Cytokinesis of micro- sporocyte meiosis is simultaneous type and results in the microspore tetrad of tetrahedral and decussate. 2 The ovary is two carpels,tetralocular,there is a ovule in each locu- le,axial placenta,the ovule is uniregmic,tenuinucellar and anatropous.Cyt- okinesis in the megaspore mother cell accompanies meiosis and the whatever one of a linear tetrad can become functional megaspore.The development of embryo sac conforms to the polygonum type.Before the fertilization two po- lar nuclei fuse to secondary nucleus and antipodal cells degenerate. 3 The development of embryo conforms to the Onagrad type.The devel- opment of endosperm is cellular type.