Continued self-pollination results in:

The correct answer is Option (2) → Inbreeding depression

Most flowering plants have bisexual flowers, so pollen easily reaches the stigma of the same flower. Continued self-pollination makes the offspring homozygous and weak, a fall in vigour and fertility called inbreeding depression. Plants have outbreeding devices to avoid it.

Option (1) Pollen-pistil interaction — Incorrect. It is the dialogue between pollen and pistil by which the pistil accepts compatible pollen; it happens in every pollination.

Option (2) Inbreeding depression — Correct. Continued self-pollination is a form of inbreeding. Continued inbreeding reduces fertility and even productivity, called inbreeding depression.

Option (3) Artificial hybridization — Incorrect. It is a plant-breeding method in which chosen pollen is put on the stigma by hand; it is done by humans, not caused by selfing.

Option (4) Emasculation — Incorrect. It is the removal of anthers before they open, a step of artificial hybridisation.

Note: A similar question was also asked in CUET (UG) 2023 on 05-06-2023 (Slot 3).

NCERT Extract:
Pollination – …