The in vivo and in vitro ovary ages are determined as days after silk appearance. 17-18 days after silk appearance, endosperm is multinuclear. In some cases, fragments of nuclear or cellular endosperm were observed. If endospermogenesis and embryogenesis proceed together in embryo sac, the last one begins earlier and passes ahead of embryo development. At the moment of fusion of polar nuclei, the embryo can contain from 2 to 100 cells.
Embryos stop development at the globular stage.
In addition, at the same stage, many embryo-like structures begin to form on the surface. They do not reach the stage of mature embryoid and are not able to form plantlets when plated on regeneration medium. The development of embryos continues in the absence of endospermal tissue. They can form plantlets or produce by gemmagenesis a great number of embryoids, able to produce plantlets. Thus, it can be suggested, that in unfertilized ovaries in vitro there is a special type of interrelationship between haploid embryo and endosperm.