Tissue culture is a technique applied to grow the tissues of plants and animals by in vitro culture. ‘In vitro’ culture means culturing the tissues outside the body of living organisms i.e. in the laboratory.
Plant tissue culture is developed based on a principle called ‘totipotency’. Totipotency is the inherent capacity of a living plant cell to develop into a complete plant of the same variety. It is a peculiar character of plants. According to this technique, if a living plant cell is isolated from a plant and introduced in the standard culture medium, it grows into a mass of undifferentiated cells called ‘callus’. When the callus is introduced into another culture medium with plant growth hormones such as auxinsand cytotkinins, it grows into a complete plant with root and shoot systems. This plant is genetically same to the plant from which the cell is taken.