Pollination is the means of sexual reproduction in plants.
Most flowering plants go for sexual reproduction by this method.
The plants secrete pollen grains (male gametes) from the anther of the flower (male organ).
This pollen reaches on to the stigma of a female organ in the flower. This flower can be of the same plant or different plant. But in most cases, it is of a different plant.
The pollen then unites with ova in the female organ of the flower to form a zygote. This zygote transforms to an embryo and then to seed which is ready for propagation into a new plant.
However, this pollination has many benefits for animals and men in daily lives.
- Helps in the maintenance of plant diversity
- Help in the sustenance of genetic resilience
- Supports plant breeding
- Supplies food for the entire food chain
- It helps in the reproduction of a few animals like birds and insects.
- Enhance agriculture yield.
Helps in the maintenance of plant resilience: Sexual reproduction enhances the genetic vitality and adaptability of plants. This makes them stronger to cope up with the ever-changing environmental and external conditions. Pollination being a process of sexual reproduction helps to maintain these plant characters.
Help in the sustenance of plant distribution: The seeds are carried by animals as a part of eating the fruit and dropped in different places. These seeds grow into plants in the distant place from mother. Such distance distribution is kept alive due to the distribution of pollen to distant parts. If not for pollination, these plants which are in distant places from the other plants of the same species do not get a chance of sexual reproduction.
Supports plant breeding: The plant breeding is done by many scientists like Gregor Mendel, Hugo de Vries, etc. This was possible through the use of techniques like self-pollination, cross-pollination, etc. This pollination is quite an easy method for genetic variation studies compared to other advanced methods.
In biotic pollination, insects and birds land over flowers to drink nectar. In doing so, some pollen sticks to their limbs which are dispersed on to other flowers.
So, flowers provide food in the form of nectar to insects and birds while getting pollinated in return.
The honey bees collect honey from flowers which are again stored in the honeycomb. We humans take it for food. Thus pollination indirectly provides food to animals.
Supports reproduction in animals. Many birds and insects have breeding time around the flowering season. This is because, during the flowering season, insects can find food in the form of nectar. They lay eggs and grow their larva as offspring. These larva in-turns become food for birds. Hence, many birds and insects reproduce during the flowering season. It is experimentally found that as the time for flowering changes, the reproduction cycle of birds and insects too change. Thus indirectly, pollination phenomena help to the reproduction cycle of birds and insects.
Enhance agriculture yield: In agriculture, there is a practice of manual pollination (mechanical pollination). Farmer uses a soft cloth to rub over different flowers like a sunflower. Doing so will enhance pollination.
Disadvantages of pollination to man:
Pollen is one of the major causes of respiratory disorders in humans. It causes asthma which is a periodic and abrupt disturbance in respiration. The person scrambles to breathe normally.
The pollen is allergic to the respiratory tract. It goes into the track along with air during inhalation. When the pollen enters the bronchi, it can evoke an immune response. The mucous tissue secretes histamine and other substances. This leads to the contraction and partial blockage of windpipe leading to difficulty in breathing.
These symptoms are particularly severe during winters.