POLLINATION

Pollination

(1) The process of transfer of pollen grains from an anther to the stigma of the same flower or of different flower.

(2) It is of two types:

(i) Self pollination: This process involves the transfer of pollen grains from the anthers to the stigma of the same flower or of another flower borne by the same plant.

(ii) Cross pollination: Cross pollination involves the transfer of pollen grains from the flower of one plant to the stigma of the flower of another plant. It is also called xenogamy.

Other form of pollination are:-

• Autogamy: Transfer of dust grains from the anther to the stigma of a similar flower is called autogamy. In such flower anthers and the stigma lie near each other with the goal that self-pollination can happen.

Chasmogamous flowers and Cleistogamous flowers: Some plants produce two sorts of flowers. For Example: Viola(Regular Pansy), Oxalis, and Commelina. Flowers with uncovered anthers and stigma are known to be chasmogamous flower. Flowers which don't open are known as Cleistogamous Flowers.

• Geitonogamy: Transfer of dust grains from the anther to the stigma of the diverse flower but of the similar plant is called Geotonogamy. Hereditarily it is like autogamy on the grounds that the dust grains originate from the same plant.

• Xenogamy: Transfer of dust grains from anther to the stigma of an alternate plant but of the same species.

Agents of Pollination: Plants utilize two abiotic (Wind and Water) and one biotic (Animals) operators to accomplish pollination. Majority of plants utilize biotic operators for pollination. Just a little extent of plants utilizes abiotic operators.

• Anemophily: The pollination happened by the impact of wind as an operator is called Anemophily.

• Hydrophily: The pollination happened by the impact of water as an operator in hydrophytes is called Hydrophily.

• Zoophily: The pollination happened by the impact of creatures as an operator is called Zoophily.

On the basis of various sorts of creatures involved in pollination, they are grouped into:

• Entamophily: The pollination happened by the impact of insects as an operator is called Entamophily.

• Ornithophily: The pollination happened by the impact of birds as a specialist is called Ornithophily.

•Chirapterophily: The pollination happened by the impact of bats as a specialist is called Chirapterophily.


Anemophily: It is the name given to the pollination by wind. Little flowers are pollinated by anemophily. These plants produce huge measure of dust grains. For Example: Sugar Stick, Grasses, Bamboo, Rice, and so on. The anemophilous flowers are small and never shaded in bright color. They are unscented and never create nectar. Pollen grains are little, dry and light. Stigmas are bushy and spread to trap dust grains floating in air.


​Hydrophily: It is the pollination by water. Not all aquatic plants experiences hydrophily. When the pollination happens underneath the water level it is called Hypohydrogamic. It found in plants like Hydrilla, Ceratophyllum. When the pollination happens at the water level is called Epihydrogamic. It is found in plants like Vallisneria.



In some other aquatic plants like water hyacinth (Eichhornia), water lily flower develops out of water and pollination happens by wind or insects. In vallisneria, the sub-consolidated aquatic plant, the male flowers opens at the surface of water. The discharged dust grains coasts on water flow. The pedicel of female flower stretches till it achieves the water surface to contact with dust grains.

• Zoophily: It is the pollination by creatures like bats, birds, insects, wasps, honey bees and so on. Majority of plants are pollinated by insects.The entamophilous flowers have some trademark highlights:


The flowers are fragrant and overlook scent. For Example: Jasmine, Rose.


The flowers are colorful to attracted insects.


The nectar organ produces nectar to encourage visiting insects.


The dust grains are sticky or spiny. It attaches to the group of visiting insects.


To catch dust grains, the stigma has to be sticky.