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刺梨胚及胚乳的发育
引用本文:李淑久,胡适宜.刺梨胚及胚乳的发育[J].Acta Botanica Sinica,1987(4).
作者姓名:李淑久  胡适宜
作者单位:贵州农学院,北京大学生物系
摘    要:本研究对单瓣刺梨胚及胚乳的发育过程进行了观察,获得如下主要结果:1.刺梨胚的发育属于紫菀型的一种变异类型。原胚发育早期,在胚体顶端具有明显的胚芽原细胞。成熟胚为典型的双子叶植物胚的形态,在子叶中贮藏大量的蛋白质粒。2.刺梨的胚乳属核型。经游离核时期以后形成胚乳细胞。紧邻胚囊周界壁的表层胚乳细胞可以进行平周分裂,产生层叠状的胚乳周缘层。此种后形成的胚乳,我们称之为次生胚乳。当次生胚乳形成时,其余的胚乳细胞逐渐解体,最后几乎完全消失。次生胚乳只在合点处解体,其余保留至种子成熟。3.发现了开花后一些胚珠中无胚或胚和胚乳在发育早期退化的现象,可认为是刺梨种子不育的一个重要原因。

关 键 词:刺梨  胚胎发育  胚乳

DEVELOPMENT OF THE EMBRYO AND ENDOSPERM IN ROXBURGH ROSE
Authors:Li Shu-jiu Hu Shi-yi
Abstract:1.The development of the embryo of roxburgh rose(Rosa roxburghii Tratt.f.normalis Rehd.et Wils.)conforms to the Asterad type with significant variation of forming an oblique wall after the division of the apical cell.A wedge-shaped epiphysis initial is cut off and re- mained in early stages of proembryo.The mature embryo is typical in dicotyledons and ac- cumunates large amount of protein bodies in its two cotyledons.2.The endosperm formation is nuclear type.Since the free nuclei become completely separated by the cell wall,the cells in the stirface layer of the cellular endosperm may divide periclinally to form a stratified cell zone,as we called secondary endosperm,lining along the boundary of the embryo sac.During the formation of secondary endosperm,the rest endosperm cells degenerate gradually.In ma- ture seed only the secondary endosperm persists and contacts directly with the mature embryo, except at the chalazal end,where it degenerates earlier.3.The results of this study reveal that degneration of embryo and endoeperm at early stages of embryogeny in some ovules,perhaps caused by the insufficiency of nutrients,may be one of the reasons of seed abortion.
Keywords:Rosa roxburghii Tratt  f  normalis Rehd  et Wils  Development of embryo  Endosperm  
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