A hybrid produced by fusions of somatic cells of two varieties or species is called somatic hybrids. The process of producing somatic hybrids is known as somatic hybridisation.
(1) The first step in somatic hybridization in the removal of cell wall by digestions with a combination of pactinase and cellulase enzyme. The plant cells lacking cell wall are called protoplasts.
(2) Fusion between protoplasts of selected parents is induced by a solution of polyethylene glycol (PEG) or a very brief high voltage electric current. When the protoplasts are cultured on a suitable medium, they regenerate cell walls and produce somatic hybrids.
(3) These hybrids give rise to callus, which later differentiates into new plants, somatic hybrids in plants were first obtained between two species of tobacco. The two uses of somatic hybridisation are :
(i) Pomato is somatic hybrid can be carried our more rapidly when plant cells are in protoplast state.
(ii) New genes can be introduced and mutations will be easier.