Apospory

Apospory

The term apospory refers to the process of suppressing the production of meiotic spores of a plant. In the Archegoniates and Phanerogams, the mother cells of the spores do not undergo meiosis and give rise, by equational mitosis, to 4 diploid cells, called pseudospores. These generate diploid gametofiti, whose gametes (pseudogametes) are diploid. The oosphere develops in a new sporophyte individual, without gamia (gonial apogamy).
In the apospory, therefore, the formation of a diploid embryonic sac (gametophyte) from cells that has not undergone the reductional division (meiosis) to spores is formed.
Somatic apospory is defined as the process in which the cell that develops is an element foreign to the archesporium, of nucellar or chalazal origin (of the ovum).
On the other hand, gonial or generative aposporia occurs when the initial cell is homologous to a mother cell of the megaspores in which, however, meiosis has been suppressed (it only undergoes mitosis which gives rise to diploid [pseudospore] cells, which generate the diploid gametophyte with diploid pseudogametes).