– Overview:
– Apical dominance promotes vertical growth by inhibiting lateral bud growth.
– Energy is directed towards upward growth for better light exposure and competition.
– The apical bud produces auxin, a hormone that inhibits lateral bud growth.
– Removal of the apical bud leads to lateral bud growth and competition for lead growth.
– Auxin regulation of apical dominance was discovered in 1934.
– Apex removal:
– Plant stages after apex removal include lateral bud formation and elongation.
– Cytokinin promotes lateral bud formation, while auxin imposes inhibition.
– Cytokinin and gibberellic acid promote lateral bud elongation and branch development.
– SAM inhibits lateral bud growth, and cutting the shoot releases cytokinin for growth.
– Lateral dominance occurs when lateral bud growth prevents upward growth.
– Applications:
– Continuous removal of apical meristems can shape trees and shrubs by promoting new branch growth.
– Pruning techniques like coppicing and pollarding manipulate apical dominance for desired plant shapes.
– Espalier, hedge building, and topiary sculptures utilize apical dominance principles.
– Fruit trees with strong apical dominance can be pruned to stimulate side limb development.
– Ballerina apple trees benefit from strong apical dominance for compact growth.
– See also:
– Meristem plays a role in plant growth and development.
– Fruit tree pruning techniques can manipulate apical dominance.
– References:
– Hormones play a crucial role in apical dominance in plant development.
– Auxin mediates apical dominance in xylem-associated or medullary cells.
– Growth substances inhibit bud development and influence plant growth.
– Studies have explored mechanisms behind apical dominance and shoot branching.
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (December 2011) |
In botany, apical dominance is the phenomenon whereby the main, central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; on a branch the main stem of the branch is further dominant over its own side twigs.
Plant physiology describes apical dominance as the control exerted by the terminal bud (and shoot apex) over the outgrowth of lateral buds.