Question

Refer the following statements.
(i) Promotes flowering in pineapple.
(ii) Used to prepare weed free lawn.
(iii) Promotes the abscission of older mature leaves and fruits.
The above functions are carried out by

• A. GA
• B. ABA
• C. Auxin
• D. Ethylene

Answer 1

The correct option is C Auxin

• Auxin help to initiate rooting in stem cuttings, an application widely used for plant propagation.
• Auxins promote flowering e.g. in pineapples.
• They help to prevent fruit and leaf drop at early stages but promote the abscission of older mature leaves and fruits.
• In higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called apical dominance. Removal of shoot tips (decapitation) usually results in the growth of lateral buds.
• It is widely applied in tea plantations, hedge-making.
• Auxins also induce parthenocarpy, e.g., in tomatoes.
• They are widely used as herbicides. 2, 4-D, widely used to kill dicotyledonous weeds, does not affect mature monocotyledonous plants. It is used to prepare weed-free lawns by gardeners.
• Auxin also controls xylem differentiation and helps in cell division.