Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

Pollen pistil interaction is the sum of all the events from the lending of pollen grains on the stigma of flower and entry of the pollen tube into the ovule of flowering plants. The process of pollination transfer the pollen grains but it never ensures that the compatible pollen of this species reaches the stigma but sometimes non-compatible type of pollen also comes to the stigma which may be either of same species or another species. The pistil has the ability to recognize the pollen whether it is the right type of pollen of this category or it is healthy. If the pollen is suitable, the pistil accepts it and encourages the post- pollination event i.e. moves
towards fertilization. If the pollen is unhealthy/noncompatible, the stigma in pistil inhibits pollen germination or rejects pollen inhibiting the pollen tube growth through style. The ability to recognize the pollen occurs due to chemical interaction of pistil and pollen. Scientists after studying the components of pollen and pistil understood the mutual interaction between them acceptance or rejection.
Pollen on being compatible, germinates on stigma and produces a pollen tube that emerges out from germ pose. This pollen tube traverses through stylar tissues and enters the ovary, from where it enters the ovule through micropyle.