Fertilization in plants, like in animals, is the process by which male and female reproductive cells combine to form a new organism. In plants, this process is essential for the production of seeds and, ultimately, the growth of new plants. Here’s an overview of the fertilization process in plants:
- Germination of Pollen: When a pollen grain lands on a receptive stigma, it may germinate. Germination involves the growth of a pollen tube down the style of the flower. The pollen tube is essential for delivering male gametes (sperm cells) to the female reproductive structures in the ovule.
- Double Fertilization: Unlike animals, where a single sperm fertilizes a single egg, plants exhibit a unique process called double fertilization. In this process, two fertilization events occur within the same ovule. The two male gametes within the pollen tube have distinct functions:
- First Fertilization Event: One of the male gametes fuses with the egg cell in the ovule. This results in the formation of a diploid zygote, which will develop into the embryo.
- Second Fertilization Event: The other male gamete fuses with two polar nuclei in the ovule, forming a triploid cell. This triploid cell will give rise to the endosperm, a nutrient-rich tissue that nourishes the developing embryo.