May 7 ~ May 10###Central nucleus microspore stage###The megaspore mother cell formation
May 11 ~ May 13###The late uninucleate stage###The megaspore mother cell meiosis to form tetrad
However, the nucellar epidermis produced a subdermal layer by periclinal division between the epidermis of the ovule and the megaspore mother cell (Fig.
In the nucellus the archesporial cell without periclinal division formed a primary parietal cell that directly developed into a megaspore mother cell on the later-June (Fig.
On June 20 a typical megaspore mother cell was first observed which could be easily recognized by its large nucleus with dense cytoplasm (Fig.
The inner integument initiates first, and then the outer integument develops into a small protuberance at the megaspore mother cell
In this primordium, an archeosporial cell produces a megaspore mother cell, which undergoes meiosis, forming a linear tetrad.
It is larger and differentiated from the neighboring cells and then become the megaspore mother cell (mc).
Reproductive modifications like apomixis, which involves the parthenogenetic development of apomeiotic eggs of unreduced embryo sacs that arise either from a somatic cell of the nucellus (apospory) or from a megaspore mother cell (MMC) with modified (meiotic diplospory) or absent meiosis (mitotic diplospory) (Nogler, 1984), have the potential of preserving heterosis over generations (Jongedijk, 1991).
In conclusion, as many as one of five megaspore mother cells in PG-F9 failed normal meiosis and gave rise directly to apomeiotic embryo sacs containing unreduced nuclei.
In addition, the megaspore mother cells
(MMCs) in ms1ms1 plants were observed to undergo meiotic division without cytokinesis after Telophase II and thus produced multiple nuclei in megagametophytes (Cutter and Bingham, 1977; Kennell and Horner, 1985; Chen and Palmer, 1985; Zhang and Palmer, 1990).
gnemon two to eight megaspore mother cells
(megasporocytes) differentiate within each ovule.