Root System

ROOT SYSTEM

•    The parts of the plant that anchor plant to the ground and remain under the ground (roots) form the root system.

•    Root systems are mainly of two types:

Tap root system:

•    In the tap root system, a single root (called the primary root) comes out from the seed after germination.

•    Tap roots are also called true roots.

•    Later, smaller roots called lateral roots branch out from this primary root.

•    Mango, Neem, Pine, Sheesham, Pea, Carrot, Radish, Turnip, and Beetroot are examples of plants in which tap roots are found.

Fibrous root system:

•    Fibrous roots grow from the base of the stem, and have a bushy appearance.

•    These roots are thin and almost equal in size.

•    Grass, Maize, Wheat, Onion, Sugarcane, and Rice are examples of plants in which fibrous roots are found.

Functions of Roots:

i.    Anchorage – Roots anchor the plant firmly to the soil (mechanical function).

Roots anchor the plant firmly to the soil and absorb water and mineral salts from the soil

ii.  Absorption – Roots absorb water and mineral salts and conduct them upwards (physiological function).

iii. Special functions – By undergoing modifications in their structure, roots perform special physiological functions like:

•    Food storage

•    Absorption of atmospheric moisture

•    Sucking food from host plant

•    Gaseous exchange

Root Modifications:

•    Roots of some plants are modified to perform additional functions.

•    For storage of food, the roots of some plants, such as radish, carrot, turnip, sweet potato, and beetroot, store food and become fleshy.

•    For climbing, some plants have climbing roots that help the plant to climb up a support such as a wall, rock, or tree, e.g., money plant, black pepper, and betel.

Money plant

•    For nutrition, plants such as dodder have specialized roots called parasitic roots arising from their stem, which help them to absorb water and nutrients from the host.

Dodder

•    Roots of plants such as dahlia and asparagus can develop into new plants.

Dahlia

•    For extra support, root of plants such as Bamboo, Sugarcane, and Banyan give out additional roots from their branches.

•    These roots grow downwards and give extra support to the stem of the plant. These are called prop roots.

•    The great Banyan tree in Sibpur, Kolkata is more than 200 years old, forming a crown of over 404 metres in circumference and has about 1600 prop roots.

Banyan tree