PGR's

Question 1

Gibberellin

Answer 1

• cause increase in length of axis
• cause fruits like apple to elongate and improve their shape
• delay senescence
• used to speed up malting process in the brewing industry
• promotes bolting in beet, cabbage, and plants with rosette habit

Question 2

cytokinins

Answer 2

• promotes cell division
• helps produce new leaves, chloroplasts, lateral shoot growth, adventitious shoot formation
• help overcome apical dominance
• promote nutrient mobilisation which helps delay leaf senescence

Question 3

ethylene

Answer 3

• promotes senescence
• abscission of plant organs especially leaves and flowers
• effective in fruit ripening
• enhances respiration rate during fruit ripening
• breaks seed and bud dormancy
• initiates germination in peanut seeds
• sprouting of potato tubers
• promotes root growth and root hair formation
• initiate flowering in mango
• promotes female flowers in cucumber
• hastens fruit ripening in tomatoes and apples
• accelerates abscission in flowers and fruits

Question 4

Abscisic acid

Answer 4

• inhibits seed germination
• stimulates closure of stomata
• increases tolerance of plants to various kinds of stresses
• plays an important role in seed development, maturation, and dormancy
• ABA helps seeds withstand desiccation
• antagonistic to GA’s