What is Embryogenesis? – Definition
Embryogenesis is the process by which embryo forms and develops, from zygote, pollen or bipolar structures from somatic cells that parallel the developmental path of zygotic embryos.
Types of Embryos and Embryogenesis
The types of embryo and embryogenesis can be summarized as follows
| Type | Embryo develops from | |
|---|---|---|
| Zygotic embryo | Zygotic embryogenesis | Zygote |
| Non-zygotic embryos | Somatic embryogenesis | Somatic cell |
| Androgenetic embryogenesis | Pollen | |
| Parthenocarpic embryogenesis | Unfertilized egg | |
Development of Zygotic Embryo
Zygotic embryo is formed following double fertilization of the ovule. After fertilization, the zygote undergoes an asymmetrical cell division that gives rise to a small apical cell, which becomes the embryo and a large basal cell called the suspensor. Suspensor provides nutrients from the endosperm to the growing embryo.
From the eight cell stage onwards, structures like shoot meristem, cotyledons, hypocotyl develop. The shoot and root meristem arise from specific groups of cells as the young embryo divides. Seeds can also develop without fertilization, which is referred to as apomixis and by a method plant tissue culture; such embryos are called somatic embryos.
To get the information about the development of somatic embryo and somatic embryogenesis visit Somatic Embryo. This page gives details on the topics along with the applications of somatic embryogenesis.