Question

Bolting, i.e., internode elongation lust prior to flowering in beet, cabbage, and many rosette plants, is promoted by

• A. auxins
• B. gibberellins
• C. cytokinins
• D. ethylene.

Answer 1

Answer: (B)

gibberellins

Certain plants show profuse leaf development but reduced internode growth. Such form of growth is called rosette, where a large number of broad leaves remain attached to a very short axis. Such plants exhibit excessive internode growth just before reproduction, the axis elongates 5-6 times the original height of the plant and starts flowering. Stimulation in the internode growth just before reproduction is called bolting. If such plants are treated with gibberellins during conditions of rosette growth, the plants bolt, and flower. Normally, bolting is favoured in nature by either cold nights or long days.

So the correct answer is 'gibberellins'.