This document provides an overview of somatic embryogenesis, which is the process where somatic cells develop into embryos. It defines somatic embryogenesis and describes the two types: direct and indirect. The key steps of somatic embryogenesis are induction, maturation, and conversion. Factors that affect the process include growth regulators, nutrients, and environment conditions. Somatic embryogenesis has applications for large scale propagation of plants, genetic studies, and production of pathogen-free plants.

2. SYNOPSIS --
 Introduction of se
Definition of se
 Types of se
 Steps of se
 Methods of se
 In monocot and Dicot
 Factor affecting
 Applications
 Conclusion
 Reference

3. • Process by which somatic cells or tissue develops into
differentiated embryo.
• Somatic embryos are formed from plant cells that are not normally
involved in the development of embryo, i.e. ordinary plant tissue.
• Somatic embryogenesis is the process in which a single cell or a
small group of cells follow a development pathway that leads to
reproducible regeneration of non-zygotic embryos which are
capable of producing a complete plant.

5. • However, the two ways of inducing somatic embryogenesis
include:
• Direct somatic embryogenesis: In this process, the embryo is
developed without any intermediate callus stage. The embryo can
be developed by directly inducing the explant for the genesis.
• Indirect somatic embryogenesis: In this process, the development of
an embryo occurs with an intermediate callus stage. So, it is a
multistep process.

6. • 1. Induction: It is the initiative phase where cells of callus are induced to
divide and differentiate into groups of meristematic cells called embryogenic
clumps (ECS).
• These Ecs develop into initial stages of somatic embryo i.e. globular stage.
• 2. Maturation: In this phase somatic embryo develop into mature embryos
by differentiating from globular to heart shaped and the mature embryo here
undergoes biochemical changes to acquire hardness.
• 3. Conversion: Embryos germinate to produce seedlings.

9. • Leaf petiole or root segments from seven day old seedlings or cambium
tissue from storage root can be used as explant.
• Following aseptic technique, explants are placed individually on a semi-
solid MS medium.
• Culture are incubated in the dark.
• In this medium the explant will produce sufficient callus tissue.
• After 4 week of callus growth, cell suspension culture is to be initiated by
transferring callus tissue to a 250 ml flask containing 20-25ml of liquid
medium of same composition as used for callus growth (without agar).

10. • Flask are placed on a horizontal gyratory shaker at 25*C.
• The presence or absence of light is not critical at this stage.
• Cell suspension are sub- cultured every 4 week by transferring 5 ml to 65
ml of fresh liquid medium.
• After 3-4 week, the culture would contain numerous embryos in different
stage of development.
• Somatic embryos can be placed on agar medium devoid of 2, 4-D for
plantlet development.
• Plantlets are finally transferred to pots for subsequent development.

11. • The addition of reduced nitrogen in the medium helps in both embryo in
association and maturation.
• In the absence of iron, embryo development fails to pass from the globular to
the heart shaped stage.
• Growth regulators in the medium specially oxygen or oxygen in combination
with cytokinins appear essential for the onset of growth and the induction of
embryogenesis.
• Cytokinins are important in somatic maturation and specially cotyledons
development.

12. • The addition of activated charcoal to the medium has proved to the useful for
somatic embryo development.
• Environment conditions of light, temperature, density of embryogenic cell in
medium a important.
• Regarding culture vessel the position of embryos and the physical state of
medium have little effect.

13. • Large scale propagation compared to zygotic embryo.
• More useful than organogenesis.
• Useful for mutagenic studies and mutant production.
• Useful for genetic manipulation technique.
• Useful for pathogen- free plant production.
• A good source of protoplast culture.