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

Suckers:• 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

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

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

Potato 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

Tubers:

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