Apical dominance means :-a)Suppression of growth of apical bud by axil...
Auxins are generally produced by the growing apices of the stems and roots, from where they migrate to the regions of their action. In most higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called apical dominance.
Apical dominance means :-a)Suppression of growth of apical bud by axil...
Explanation:
Apical dominance is a phenomenon where the growth of the main shoot apex (apical bud) is dominant over the growth of axillary buds. This is due to the presence of auxins, a plant hormone, which is produced in the apical bud and transported downwards to the axillary buds.
The process of apical dominance can be explained as follows:
Suppression of growth of axillary buds by the presence of apical bud
- The apical bud, which is at the top of the plant, produces auxins.
- These auxins move downwards and reach the axillary buds.
- The auxins inhibit the growth of the axillary buds and prevent them from growing into branches.
- As a result, the plant grows taller and does not branch out.
Stimulation of growth of axillary buds by removal of apical bud
- When the apical bud is removed, there is no source of auxins.
- This allows the axillary buds to grow and develop into branches.
- This is useful in horticulture, where pruning is used to promote branching and bushiness in plants.
Inhibition of growth of axillary buds by removal of apical bud
- If the apical bud is removed, but some of the stem that contains auxins is left behind, the axillary buds near the cut stem will not grow.
- This is because the auxins are still present and continue to inhibit the growth of the axillary buds.
Conclusion:
Apical dominance is an important concept in plant growth and development. It is responsible for the growth of the main shoot apex and suppression of the growth of axillary buds. The removal of the apical bud can stimulate the growth of axillary buds, but if auxins are still present, the growth of axillary buds can be inhibited.