Page 149 - phytochemistry general program

should be added in higher concentration (up to 30 mg/L) than the synthetic
auxines which are not subjected to the same enzymatic oxidation. Therefore 2, 4-

D are added in lower concentrations (0.1 –2 mg/L).

b) Cytokinins
They are produced primarily in root meristems, young leaves, and young fruits,

and seeds

Functions of Cytokinins:
• Stimulates cell division
• Stimulate morphogenesis (shoot initiation/bud formation) in tissue

culture.
• Stimulate the growth of lateral (or adventitious) buds release of apical

dominance
• Stimulate leaf expansion resulting from cell enlargement.
• Stimulate the dark-germination of light-dependent seeds.

• Delays senescence.

The most widely used cytokinins in culture media are kinetin, benzyladenine
(synthetic) and zeatin (natural). Kinetin is added in a concentration of 0.1mg/L for

the induction of the callus.
These are compounds that promote cell division in plant tissue, regulate

growth and development and retard plant aging.

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