Regeneration Methods of Plants in Culture

It includes two methods:

1. Organogenesis
2. Somatic Embryogenesis

Organogenesis 

In plant tissue culture, it refers to the formation of either shoot or root. The equilibrium of auxin and cytokinin and the tissue’s capacity to react to phytohormones during culture are key factors in in-vitro organogenesis. In-vitro organogenesis can be of two types: 

1. Indirect organogenesis
2. Direct organogenesis

• Indirect organogenesis involves the formation of organs indirectly via a callus phase. For the production of transgenic plants, induction of plants through a callus phase has been used. Either the callus is transformed, plants are regenerated, or the primary explant is transformed, and the callus is formed, and then shoots are cultivated from the explant. It is more important for transgenic plant production.
• Direct organogenesis involves direct bud or shoots formation from the tissue without a callus stage. Plants are usually propagated by direct organogenesis for improved multiplication rates and production of transgenic plants but mainly for clonal propagation. 

Somatic Embryogenesis

Somatic embryogenesis is a nonsexual developmental process that produces a bipolar embryo with a closed vascular system from the somatic tissues of a plant. It has become one of the most powerful techniques in plant tissue culture for mass clonal propagation. Somatic embryogenesis may occur directly or via a callus phase. For clonal propagation, direct somatic embryogenesis is preferred since there is less chance of somaclonal mutation.

Indirect somatic embryogenesis is usually used in the selection of desired somaclonal variants and for the production of transgenic plants.

Encapsulated somatic embryos are known as synthetic seeds. Synthetic seeds have multiple advantages. They are easy to handle, they can potentially be stored for a long time, and there is potential for scaleup and low cost of production.