Embryogenesis is the process of initiation and development of an embryo from a zygote (zygotic embryogenesis) or a somatic cell (somatic embryogenesis). 

Embryo development occurs through an exceptionally organized sequence of cell division, enlargement and differentiation. Zygotic and somatic embryos share the same gross pattern of development.

          Zygotic Embryo

Somatic Embryonic Cell

Both types of embryos develop as passing through typical developmental stages, such as globular, scutellar and coleoptilar stages for monocots, or globular, heart, torpedo and cotyledonary stages for dicots and conifers. Embryo development is bipolar, having a shoot and a radicular pole at opposite ends. 

                                                           Zygotic Embryo Chart

                                                            Somatic Embryo Chart

Copyright 2000

Development of this lesson was supported in part by Cooperative State Research, Education, & Extension Service, U.S. Dept of Agriculture under Agreement Number 98-EATP-1-0403 administered by Cornell University and the American Distance Education Consortium (ADEC).  Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.