Somatic Embryogenesis

The process of embryo development is called embryogenesis. It is not the monopoly of the egg to form an embryo. Any cell of the female gametophyte (Embryo sac) or even of the sporophytic tissues around the embryo sac may give rise to an embryo. Thus we can say that 'The phenomenon of embryogenesis is not necessarily confined to the reproductive cycle". In this subsection we will discuss - some examples of "embryos formed in culture", also referred to as "somatic - embryos".

The first observation of somatic embryos was made m Daucus Carota. Other plants in which the phenomenon has been studied in some detail are Ranunculus sceleratus, citrus and coffea spp. In Ranunculus sceleratus somatic as well as various floral tissues, including anthers proliferated to form callus which, after limited unorganized growth differentiated several embryos. These embryos germinated in situ and a fresh crop of embryos appeared on the surface of the seedling. The embryos were derived from individual epidermal cells of the hypocotyl.