Introduction

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. 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

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. Potato Tubers 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

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