1. Introduction
The plants can be propagated by specialized structures like Suckers, Bulb, Corms, Tubers, Rhizomes in a short duration.
Propagation by these underground structures is an essential method of vegetative reproduction in horticultural nursery business
Types of Specialized Structures:
Suckers- eg. Banana
Bulbs- eg. Onion
Corms- eg. Gladiolus
Tubers- eg. Potato
Rhizomes- eg. Ginger

2. Water and Sword Suckers of Banana
Sucker is a lateral branch developing from underground parts of the stem or roots.
Suckers arise from below the surface of soil.
The tendency of suckering is possessed only by a few plants.
Banana develops 2 types of suckers, the sword suckers and water suckers.
Sword Suckers are used for propagation of banana.
Water and Sword Suckers of Banana

3. Bulbs: Bulbs are produced by monocotyledonous plants.
A bulb is a specialized underground organ with a short, fleshy, apical growing point enclosed by thick fleshy scales.
The outer scales are generally fleshy & contain reserve food materials.
Onion, Bulbous Iris.
Onion, Bulb
Iris Bulb

4. Corms:
Corm is the swollen base of a stem whose axis is enclosed by dry, scale like leaves.
A corm is stem structure with nodes & internodes.
The bulk of corm consist of food reserves.
Gladiolus Corms

5. Tubers: Tuber is the short terminal portion of an underground stem.
Food accumulates in the form of starch in a tuber which results in thickening.
It develops buds which produce new plants on onset of favorable conditions
Potato Tubers

6. Rhizomes:
A rhizome is a horizontal stem growing either underground or along the surface of ground.
It is main axis of the plant, producing roots on its lower surface and leaves, flowering shoots above the ground.
Rhizomes show nodes internodes just like the aerial stem.
Rhizome of Ginger