To dissect and display the pollinia of Calotropis

Experiments

Exercise : To dissect and display the pollinia of Calotropis

Aim:

To dissect and observe the structure of pollinia and understand the mechanism of pollination in Calotropis flowers. (Translator Mechanism)

Principle:

In Calotropis the pollen in each anther lobe of a stamen unites into a mass, forming a pollinium.

Requirements:

Flowers of Calotropis, dissection needle, dissection microscope ,slide, blade, glycerine, coverslip, scissors.

Procedure:

Take a mature flower of Calotropis. Observe the parts of the flower and remove the calyx and corolla with the help of scissors. Identify the pentangular stigmatic disc. Insert the needle at the angles of the stigma where the pollinia are adhered. Dissect it and place the pollinia on a clean slide. Mount it in glycerine and place a coverslip on it. Observe the pollinia under the dissection microscope and record your observation.

Observation:

The stamens of Calotropis produce pollinium. Two pollinia are found attached to a glandular adhesive disc called corpusculum by a thread like structure called retinaculum. The whole structure looks like inverted letter ‘Y’ and is called translator. The sticky disc gets attached with the legs of pollinator (bees or butterflies) and is carried to the stigma of another flower, thus ensuring pollination.

Inference:

The structure of pollinia of Calotropis is well suited to achieve pollination.