Somatic embryogenesis is a process in plant tissue
culture that involves the formation of embryos from somatic cells, which are
non-reproductive cells in the plant body. This process can be induced in vitro,
under controlled conditions, by manipulating the growth regulators and
environmental conditions. Somatic embryogenesis is an important technique in plant
biotechnology as it provides a means of producing large numbers of genetically
identical plants for various applications, such as crop improvement, genetic
engineering, and conservation of endangered species.
The process of somatic embryogenesis can be divided into
several stages, which include:
- Induction:
The first stage involves the induction of somatic embryogenesis by
exposing the plant tissue to appropriate growth regulators, such as auxins
and cytokinins. The type and concentration of these growth regulators can
vary depending on the plant species and tissue type being cultured. The
induction phase typically takes a few weeks and leads to the formation of
small, globular structures called somatic embryos.
- Proliferation:
The somatic embryos that are formed in the induction phase can be further
proliferated by subculturing them onto fresh media with appropriate growth
regulators. This allows for the formation of large numbers of somatic
embryos, which can be used for subsequent stages of the process.
- Maturation:
Once the somatic embryos have been proliferated, they are transferred to a
maturation medium that contains lower levels of auxins and cytokinins.
This stage of the process mimics the physiological changes that occur
during the maturation of zygotic embryos in vivo. The somatic embryos undergo
a process of desiccation and develop the ability to germinate.
- Germination:
The final stage of somatic embryogenesis involves the germination of the
somatic embryos to form whole plantlets. The somatic embryos are
transferred to a medium that promotes rooting and growth of shoots. Once
the plantlets have developed roots, they can be transferred to soil and
grown into mature plants.
The benefits of somatic embryogenesis include the ability to
produce large numbers of genetically identical plants with desirable traits.
This technique can also be used to produce plants that are difficult to
propagate by other means, such as cuttings or seedlings. Somatic embryogenesis
can also be used for the conservation of rare and endangered plant species by
preserving their genetic diversity in vitro.