The cytokinins are plant hormones primarily responsible for cell division (cytokinesis). Kinetin was first discovered by Skoog and Miller (1955) in coconut milk. Chemically kinetin is a derivative of adenine.
Zeatin is an example of naturally occurring cytokinin and has been obtained from the maize grains. Cytokinins are produced in the roots and translocated to aerial parts through xylem. The functions of cytokinins on plants are as follows:-
(1) Induce cell division especially in the presence of auxins.
(2) Help in breaking of dormancy.
(3) Influence growth and differentiation.
(4) Delay senescence.