Question

Commonly used auxin in callus and suspension cultures is

• A. Napthalene acetic acid
• B. Indole-3-butyric acid
• C. 2, 4, 5-trichlorophenoxy acetic acid
• D. dichlorophenoxy acetic acid (2-4 D)
• E. Abscisic acid

Answer 1

The correct option is B Indole-3-butyric acid

Napthalene acetic acid (NAA): Is a colourless solid soluble in organic solvents. It is a synthetic plant hormone in the auxin family and is toxic to plants at higher concentrations. NAA has been shown to greatly increase cellulose fiber formation in plants when paired with another phytohormone called as gibberellic acid. It prevents premature falling or thinning of fruits from the stem.
Indole-3-butyric acid (IBA): This is also a plant hormone and belong to the auxin family. Plays a role in root induction and callus formation during micropropagation.
2, 4, 5-trichlorophenoxy acetic acid: A synthetic auxin, is a chlorophenoxy acetic acid herbicide used to defoliate broad-leafed plants.
Dichlorophenoxy acetic acid (2-4 D): Most common systemic herbicide used in the control of broad leaf weeds.
Abscisic acid: Owes its names to its role in the abscission of plant leaves.
Thus, the correct answer is option B.