J Integr Plant Biol. ›› 1996, Vol. 38 ›› Issue (4): -.

• Research Articles •    

Changes of Plastids Mitochondria and Their DNA in the Egg Cell Before and After Fertilization in Pharbitis

Hu Zan-min and Hu Shi-yi    

Abstract: The ultrastructure and cytoplasmic DNA in the egg cell and zygote of Pharbitis purpurea, (L.) Voyght and P. limbata Lindl. which were studied with electron microscopy and DNA epifiuorescence microscopy. The egg cell before fertilization was highly vacuolated with only a few cytoplasmic plastids and mitochondria. Plastids were spherical and/or rod- shaped containing 1 ~ 2 large starch grains. Most of the mitochondria were cup and/or circular. The cytoplasm in the zygote was much more abundant than that in the egg cell. The number of plastids and their electronic density were greatly increased, in most of which containing osmiophilic bodies. The mitochondria were rich and spherical-shaped in the zygote. Two types of cytoplasmic DNA nucleoids were detected in the egg cell, the more abundant one being big and circle-shaped and the other dot-shaped. Only dot-shaped nucleoids were present in the zygote. The content of nucleoids in the zygote was much less than that in the egg cell. Authors propose that some cytoplasmic DNA may degenerate after fertilization. The ultrastructural characteristics of the egg cell and the reduction of cytoplasmic DNA in the zygote may related to the mechanisms of plastid unipaternal inheritance in Pharbitis.

Key words: Pharbitis, Egg cell, Zygote, Ultrastructure, Cytoplasmic nucleoid

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
备案号:京ICP备16067583号-22