Fertilization in Plants – in detail

Fertilization in plants is the process by which male and female gametes (reproductive cells) fuse to form a zygote, initiating the development of a new individual. In flowering plants (angiosperms), fertilization involves the fusion of male gametes, contained within pollen grains, with female gametes, located in the ovule within the ovary of a flower. This process is essential for the production of seeds, which develop into new plants.

The transfer of pollen (containing male gametes) from the anther of a flower to the stigma of the same or another flower. This can occur through various means, such as wind, water, or animal pollination.

• Once the pollen reaches the stigma, it germinates, forming a pollen tube.

• The pollen tube grows down the style of the flower, reaching the ovary where the ovules are located.

• This unique feature in angiosperms involves the fusion of two sperm nuclei with two different nuclei in the ovule:

• One sperm nucleus fuses with the egg cell, forming a diploid zygote.
• The other sperm nucleus fuses with two other nuclei in the female gametophyte, forming a triploid cell that develops into the endosperm.

• The fertilized ovule develops into a seed, containing the embryo (zygote) and surrounded by protective seed coats.

Fertilization ensures genetic diversity by combining genetic material from two parent plants and is a crucial step in the plant life cycle, contributing to the continuity of plant species.