A membrane-bound cell with all the components of cell, formed after the cell wall is removed from a microbial or plant cell by the action of pectinase and cellulase is called protoplast.

Somatic cell Hybridization: The fusion of plant protoplasts derived from somatic cell that differ genetically. It is the method of hybrid production through fusion of somatic protoplast under in vitro conditions and subsequent development of heterocaryon to a hybrid plant.

Protoplast fusion: A technique for producing somatic hybrids between two sources of protoplasts by treating with agent such as polyethylene glycol (PEG) and Ca+2 ions to induce cell membrane fusion, The two protoplast sources may be from the same or highly different species.