Callus culture

• Cultivation of callus usually on solidified medium and initiated by inoculation of small explant in preestablished organ or culture.
• Callus formation is governed by:

a) Source of explant (meristematic tissue is better than lignified tissue)

b) Nutritional composition of medium

c) Environmental factors

Phases of callus growth

a) Lag phase: Cells prepare to divide

b) Exponential phase: Rate of cell division is highest

c) Linear phase: cell division slows down but rate of cell expansion increases

d) Deceleration phase: rate of cell division and elongation decreases

e) Stationary phase: number and size of cells remains constant

Steps of callus culture

a) Aseptic preparation of plant material.

b) Selection of nutrient media

c) Incubation of culture under controlled physical condition.