Class XII Practical: Slide Preparation - Germination of Pollen Grains

Objective

To prepare a temporary mount of germinating pollen grains and observe the development of the pollen tube.

Guidelines

1. Pollen Collection: Collect fresh pollen grains from a mature flower (e.g., Hibiscus, Petunia, Balsam).
2. Germination Medium: Prepare a sugar solution (e.g., 10% sucrose solution) on a clean glass slide. A drop of boric acid can be added to enhance germination.
3. Inoculation: Dust the pollen grains onto the drop of sugar solution.
4. Incubation: Keep the slide in a moist chamber (e.g., a petri dish with moist filter paper) for 15-30 minutes or longer, depending on the pollen type.
5. Observation: Observe the slide under a compound microscope. Look for pollen grains that have developed a pollen tube emerging from the germ pore.
6. Drawing: Draw neat, labeled diagrams of germinating pollen grains showing the pollen tube.

Expected Outcome

Microscopic observation of pollen grains with elongated pollen tubes, illustrating the initial stage of fertilization in flowering plants.