Pollination is the transfer of pollen grains from the anther of one flower to the stigma of the same or another flower. When pollen grains from the anther are transferred to the stigma of the same flower or a flower of the same plant is called self-pollination. Self-pollination leads to the production of plants with less genetic diversity, since genetic material from the same plant is used to form gametes, and eventually, the zygote. Self- pollination is said to reduce the vigor and vitality of the race as there are no new features introduced.
As this type of pollination takes place between two flowers having a similar genotype, the genotype of the produced seeds remains unchanged. It is said to be the first process of sexual fertilization in flowering plants. So the plants that produce from these seeds have got the character just like the mother plant. Pollen grains contain the male gamete and are present in the anthers of the flower. In this way, the hereditary character remains similar i.e. it maintains the purity of species. So the plants that produce from these seeds have got the character just like the mother plant. In this way, the hereditary character remains similar i.e. it maintains the purity of species. This is most significant in self-pollination.
Self-pollination is the principle mating system found in grain crops and in many vegetables. As this type of pollination takes place between two flowers having a similar genotype, the genotype of the produced seeds remains unchanged. The majority of the 50–60 main grain crops of the world are predominantly self-pollinated. It occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Self-pollination occurs in a small number of plants in nature. Self-pollination takes place in flower-like Bean, Tomato, Commelina, etc.
Merits of Self -pollination:
- In self- pollination, there is no diversity in the genes and therefore the purity of the race is maintained.
- Pollination is ascertained.
- Very few pollen grains are lost.
- Maintains the purity of species.
- Less dependent on external agents.
- Self- pollination ensures that recessive characters are eliminated.
- The plants do not depend on external factors for pollination and even smaller quantities of pollen grains produce have a good success rate in getting pollinated.
Demerits of self-pollination:
- No new variety is produced as there are no combinations of new characters.
- Produce weaker progeny with less vitality.
- New progeny are borne with less adaptability.
- The species may extinct in the future.