Dispersal of seeds by various agents

Exercise : Dispersal of seeds by various agents

Aim: To study and understand the agents that help in the dispersal of fruits and seeds.

Principle: The dissemination of seeds and fruits to various distances from the parent plant is called seed and fruit dispersal . It takes place with the help of ecological factors such as wind, water and animals.

Requirements: Fruits of Tridax, Coconut and Achyranthes, knife, forceps, petridish, hand-lens etc.

A.  Dispersal by wind – Anemochory (Example: Tridax)

Diagnostic Features

·        Fruits are light so that wind may carry them away.

·        Fruits are minute, very small and with inflated covering.

·        Fruits have feathery appendages (pappus) which greatly increase their buoyancy to disperse in high altitudes.

B.  Dispersal by water – Hydrochory (Example: Coconut)

Diagnostic Features

·        Fruits have outer coats that are modified to enable them to float.

·        The mesocarp of coconut is fibrous, which is easily carried away by water currents.

C. Dispersal by animals –Zoochory (Example: Achyranthes)

Diagnostic Features

·        Fruits are provided with hooks, spines, bristles, stiff hairs, etc. on their outer coat.

·        The sharp pointed fruits of Achyranthes stick to the hairs of the animals and clothes and get carried away from one place to another.