Megasporocyte formation in Pisum sativum L. against the back ground of bud development

Megasporocyte formation in Pisum sativum L. takes place at the stages of bud development, when the vexillum surpasses the lower androecium whorl slightly at the beginning, and markedly in further stages. Under the epidermis of an ovule, a multicellular archesporium is formed. Mitotic division of these cells gives rise to a two-layered parietal tissue and to a group of megaspore mother cells (MMCs). The tetrad is formed from one megasporocyte. In the bud development of Pisum sativum the carpel walls accrete to each other relatively early.