The main difference between pollination and fertilization is that pollination is the transfer of pollen from one flower to another while fertilization involves the fusion of male and female gametes of plants.
Pollination vs. Fertilization
Like all other organisms, plants can also reproduce sexually. To increase their population size and to transfer their characters from one generation to another generation, they reproduce in two ways, i.e., pollination and fertilization. Like animals, plants also have male and female gametes, i.e., sperms and egg. The transfer of male gametes to the female gametes is known as pollination while the process of fusion of these gametes is known as fertilization. So, pollination takes place before fertilization. Pollination takes place in flowering plants only, but fertilization occurs in almost every plant and organism on this earth.
What is Pollination?
In the 18th century, the process of pollination was discovered by Christian Sprengel. The word “Pollination” is derived from the word pollen, which is the sperm of the plant. So, pollination is the transfer of male gametes to the female gamete. Male gametes or pollen grains are produced in the male reproductive organ which is called anther. Anthers are present at the tip of a stalk known as a stamen. The female reproductive part of the flower is known as a stigma. It occurs at the tip of the female organ called the pistil. It helps in the transfer of sperms from stigma to the eggs which are located in the ovary. Pollination requires external factor for the transfer of pollen from the anther to stigma like wind, birds, insects and other animals, etc. Pollination is divided into two types, i.e., self pollination and cross pollination.
- Self pollination is a type of pollination in which anthers are transferred to the stigma of the same flower or the flower of the same plant, e.g. Capsella rubella, Bulbophyllum bicoloratum, etc. Self pollination is further divided into two types, i.e., autogamy and geitonogamy. Autogamy is a type of self pollination in which pollens transferred on the stigma of the same flower. Geitonogamy is a type of self pollination in which pollens transferred on the stigma of the different flower of the same plant.
- Cross pollination is a type of pollination in which pollens are transferred to another plant of the same species. This process takes place in some vegetables and fruits etc.
What is Fertilization?
Fertilization is a process of union of egg and sperm. It takes place after pollination. During fertilization, egg and sperm that contains the genetic material of their parents fused to form the zygote. This zygote gives rise to a new plant. As the pollen grain comes in contact with stigma, a thin tube-like structure is formed along with sperm known as pollen tube. This tube passes through another tube-like female structure known as a style and expands up to the opening of the ovary. There, sperms and egg fuse to form zygote and fertilization completed. So, fertilization takes place deep inside the flowering plant. It does not need any external factor and not divided into any other type.
- The process of transfer of male gametes towards the female gametes in the same or different flower is known as pollination while the process of union of male and female gametes is known as fertilization.
- There is no formation of the pollen tube during pollination whereas formation of the pollen tube during fertilization takes place that helps in transferring male gametes to the female gametes or egg.
- Pollination is an external mechanism and takes place outside a flower, but fertilization is an internal mechanism and takes place inside the flowers.
- Pollination occurs before fertilization, but fertilization occurs only after pollination.
- Pollination takes place in flowering plants only while fertilization occurs in almost every living being of this earth.
- Pollination requires external factors like wind, animals, insect, etc. for the dispersal of pollens while fertilization does not require any factor.
- Pollination is divided into two main types, e.g. self pollination and cross pollination while fertilization is not divided into any type.
From the above discussion, it is concluded that Pollination and fertilization are two ways of sexual reproduction but with different features. Pollination is the mechanism of transfer of pollen grains from the anther to stigma through external factors like wind, birds, and animals, etc. while fertilization is the union of male and female gametes to form zygote by forming pollen tube.