Step 1: Understand pollen–pistil interaction.
Pollen–pistil interaction refers to the series of events that occur after pollen grains land on the stigma of the pistil. The pistil recognizes whether the pollen is from the same species (compatible) or from a different or incompatible source.
Step 2: Recognition and acceptance of pollen.
If the pollen grain is compatible, the stigma allows it to germinate and form a pollen tube. The pollen tube grows through the style and reaches the ovule, enabling fertilization. If the pollen is incompatible, the pistil prevents its germination or blocks the growth of the pollen tube.
Step 3: Importance in hybrid formation.
In artificial hybridisation, pollen–pistil interaction ensures that only selected and compatible pollen grains successfully germinate and fertilize the ovule. This helps plant breeders obtain the desired hybrid offspring with specific traits from both parent plants.
Final Answer:
The role of pollen–pistil interaction in hybrid formation is to recognize and allow compatible pollen grains to germinate and fertilize the ovule, ensuring successful formation of the desired hybrid.