The process of fusion of protoplast of somatic cells derived from different varieties and or species of plants on a suitable nutrient medium to produce the somatic hybrids is called somatic hybridization. For example pomato is the somatic hybrid obtained by the protoplast fusion of tomato and potato.
The steps involved in somatic hybridization are :
(i) Single cells isolated from the selected plants.
(ii) Removal of cell wall of the fusing cell with the help of the enzymes like pectinase and cellulase. These enzymes digest the cell wall to expose the naked protoplast.
(iii) The isolated protoplasts of selected Parents are fused to obtain hybrid protoplast on special nutrient medium under aseptic conditions. This fusion is induced by the use of polyethylene glycol (PEG) or by a brief high voltage electric current.
(iv) The hybrid protoplast are cultured on suitable nutrient medium, where they regenerate cell wall and begin to undergo division to form new plantlets. These plantlets are the somatic hybrids.
Use of somatic hybridization :
- Species of plants in which sexual hybridization or breeding is not possible can be hybridized by somatic hybridization.
- Somatic hybridization Produces hybrids between those lines or species where it is not possible through sexual hybridization.
- This technique is useful in raising all opolyploids.
