石榴雌蕊分化,发育及其结构的研究

石榴具有2轮心皮,形成独特的合心皮雌蕊;子房中具有2种不同类型胎座:下部为中轴胎座,通常为3室,上部为侧膜胎座,5—10室(室数随位置而变化)。胚珠为具有两层珠被的、厚珠心型的倒生胚珠,珠心由周缘组织扩展而成。1个孢原细胞可直接发育或分裂形成1至多个大孢子母细胞,但只有1个正常发育。线型排列的四分体中,合点端的1个具有功能,其余3个退化。石榴胚囊的发育方式属蓼型,成熟胚囊中极核在受精前靠拢,但未发现愈合,3个反足细胞中一个退化较早。

Differentiation, Development and Structure of Pomegranate Pistil

A pistil of pomegranate is syncarpus of 2 whorl carpels. There are 2 kinds of placentations:the axile placentation with 3 fundamental locules in the lower part of the ovary and the parietalwith 5 fundamental locubes in the upper part. The origin of the false septum of the overy of theplant is complicated. An ovule of pomegranate is an anatropus ovule with 2 layers of integuments and a large nu-cellus that results from dividing and enlarging of a pariental cell. One or several megasporocytes of the plant resulte from the mitotic division of one archespo-rial cell and among several megasporocytes only the one functions and the others degenerate. Themegasporocyte undergoes 2 meiotic division resulting in the formation of a linear tetrad of haploidmegaspores. The chalazal megaspore enlarges in preparation for the first mitotic division of the ga-metophyte. The others degenerate. The type of development of the embrye-sac of pomegranate ispolygonum type.