Types of Pollination

Pollination is transferring pollen from the male anther to the female stigma of a plant. It forms an essential part of the plant reproduction process that leads to fertilization and the production of seeds. There are two types of pollination: Self-pollination and cross-pollination. The other types of pollination include Entomophily, Ornithophily, Geitonogamy, Chiropterophily, Hydrophily, and Zoophily. Various pollinating agents that carry the pollen grain are wind, water, insects, birds, bees, and animals. In this article, we will study pollination, its Types, pollinating agents, and its advantages and disadvantages.

Pollination Definition

Pollination is the process of transferring pollen grain from the male reproductive organs (anthers) to the female reproductive organs (stigma) of a plant.

What is Pollination?

Pollination is an important reproductive process in flowering plants where pollen, containing male gametes, is transferred from the anthers to the female reproductive organ, stigma. The transfer of the pollen grain can occur through diverse mechanisms, including wind, insects, birds, bats, water, or even the plant itself. It results in fertilization and development of seed which ensures the continuation of the species. Pollination often take place in the plant of the same species. There are different types of pollination, each involving different agents and mechanisms. Pollination can be broadly classified into two types: cross-pollination and self-pollination.

Types of Pollination

The types of pollination of plant depends on various factors including the type of species, environmental conditions, and the availability of suitable pollinators. The types of pollination is discussed in detail as follows:

Self Pollination

Self pollination is a process where pollen from the same plant reaches the stigma of a flower or ovule. This can occur in both angiosperms (flowering plants) and gymnosperms (non-flowering plants like conifers). Self- pollination can be further divided into two types: Autogamy and Geitonogamy.

Autogamy

Autogamy is a form of self fertilization where fusion of two gametes from the same individual take place. It is most commonly observed in the form of self-pollination.

• Autogamy is generally avoided in nature as the seeds produced result in subsequent species with low genetic diversity.
• This type of pollination can be seen in wheat, rice, pea, and other crops.

Geitonogamy

Geitonogamy is a type of self-pollination that involves the transfer of pollen grains from the anther of one flower to the stigma of another flower on the same plant.

• Functionally it is similar to cross-pollination, but genetically similar to autogamy.
• It requires pollinating agents, such as wind, insects,birds,etc. A pollinator can visit multiple flowers on the same plant to complete the process of pollination.
• Examples: Monoecious plants like maize.

Advantages of Self- Pollination

Self pollination have several advantages that includes:

• Self-pollination preserves the genetic properties of a species.
• Plants need not depend on the external pollinating agents like wind, insects or birds for pollination.
• Self-pollination ensures seed production.
• There are fewer chances of pollination failure.
• Self-pollination avoids pollen grain wastage.
• Flowers don’t need to produce scent, nectar, or be colored to attract pollinators.

Disadvantages of Self-Pollination

Some of the disadvantages of self-pollination are as follows:

• Seeds are produced in small quantity and are of low quality.
• Self-pollination can lead to a lack of variation, which means there is no adaptation to changing environments or potential pathogen attacks.
• It prevents the creation of new plant varieties.
• Self-pollination doesn’t introduce new characteristics, which can decrease the immunity of the offspring.
• It doesn’t allow weaker strains to be eliminated.

Cross Pollination

Cross Pollination is a process that occurs when pollen from one flower is transferred to the pistils of another flower. This occurs between flowers on different plants of the same species. Unlike self-pollination, cross-pollination involves the exchange of genetic material between different individuals. Cross pollination requires pollinating agents like insects, bees, birds,etc. Cross- pollination can be further divided into following types:

Entomophily (Insect Pollination)

Entomophily, or insect pollination, is a type of pollination where insects such as bees, butterflies, moths, beetles, and flies distribute pollen from plants. Flowers that are pollinated by insects are often brightly colored and have fragrance and produce nectar. Insects are attracted to these flowers by their color and scent. Some examples of crop plants that are pollinated by bees include: Cotton, Sunflower, Flax, Lychee.

Anemophily (Wind Pollination)

Anemophily, or wind pollination, is a method of pollination that uses air currents to transfer pollen. Anemophilous flowers are usually small and inconspicuous, and do not possess a scent or produce nectar. Plants that are pollinated by winds release large quantities of lightweight, airborne pollen. Almost all gymnosperms are anemophilous including grasses (like corn and wheat), sedges, and rushes.

Zoophily (Animal Pollination)

Zoophily, also known as zoogamy, is a type of pollination where animals such as Birds, bats, and small mammals transfer pollen. Plants that pollinate through this method have flowers with hairy pollen grains that stick to the bodies of animals. It is a mutually beneficial process for both plants and animals. Examples: Hummingbirds are bird pollinators, and bats play a role in pollinating some night-blooming flowers.

Hydrophily (Water Pollination)

Hydrophily is a type of pollination that occurs when water acts as the agent of pollination. Plants that are pollinated by water are small and inconspicuous, have long, sticky, but unwettable stigma, light and unwettable pollen grains due to mucilage cover and do not contain nectar or any fragrance. Examples: Some submerged aquatic plants, like Seagrasses, Hydrilla, Vallisneria, Zosteria, Water hyacinth, Water lily rely on water for pollination.

Ornithophily (Bird Pollination)

Ornithophily, also known as bird pollination, is the process of birds transferring pollen from the anther to the stigma of a flower.  Flowers pollinated by birds have bright colored petals, produce large amounts of nectar, and have tubular shapes to accommodate the beaks of birds. Examples of bird pollinators include hummingbirds and sunbirds, they pollinate certain species of fuchsia or salvia.

Chiropterophily (Bat Pollination)

Chiropterophily is a type of pollination that occurs when bats pollinate flowers. The flowers that are pollinated by bats are called chiropterophilous flowers. It is most common in tropical and desert areas, where many plants bloom at night. The flowers that are pollinated by bats are often white or dull in color, open at night, and have a musty or rotten smell. They are also rich in nectar. Examples: Agave plants are often pollinated by bats.

Advantages of Cross Pollination

Various advantages of cross pollination are:

• Cross-pollination between two different varieties of the same species, or even two species, results in new varieties that produces healthy offsprings.
• Seeds are produced in more significant quantities and have high strength and survivability.
• Genetic recombination during fertilization causes the hereditary traits in the lineage to disappear.
• Cross-pollination brings about variation in species. Variation brings new traits to the plant which may be advantageous to the plant. For example, it helps the new plant to defend against diseases.

Disadvantages of Cross Pollination

Some disadvantages of cross pollination are:

• Cross-pollination can introduce undesirable traits.
• A large amount of pollen must be produced to ensure pollination, which results in a lot of waste.
• Pollination may fail due to distance.
• Pollination is not always certain because a pollinator is always required.
• There is a chance of genetic recombination, which can lead to the elimination of good qualities of the parent.

Pollinating Agents

For the process of pollination plants utilize both biotic and abiotic pollinating agents. These are discussed in detail as follows:

Biotic Pollinating Agents (Living Organisms)

Biotic pollinating agents are living organisms that carry pollination. These are:

• Insects (Entomophily): Bees, butterflies, moths, flies.
• Birds (Ornithophily): Hummingbirds, and sunbirds.
• Bats (Chiropterophily): Bats, especially in tropical regions
• Animals (Zoophily): Includes mammals, and birds.

Abiotic Pollinating Agents (Non-Living Factors)

Abiotic pollinating agents are non-living things that carry pollination. These are:

• Wind (Anemophily)
• Water (Hydrophily)

Difference Between Self-Pollination and Cross-Pollination

The difference between Self-Pollination and Cross-Pollination are as follows:

Feature	Self-Pollination	Cross-Pollination
Definition	Pollen from the same flower or plant fertilizes the ovules within that flower or plant.	Pollen from one flower or plant is transferred to the stigma of another flower or plant.
Mechanism	Autogamy (transfer of pollen within the same flower) or geitonogamy (transfer of pollen between flowers on the same plant).	Involves the transfer of pollen between flowers on different plants.
Genetic Diversity	Low genetic diversity. Offspring are genetically identical to the parent plant.	High genetic diversity. Offspring inherit genetic material from two different parent plants.
Advantages	No dependency on external pollinating agents.	Greater genetic variability, promoting adaptability to changing environments.
Disadvantages	Limited genetic diversity, making the population susceptible to diseases and environmental changes.	Requires external agents (wind, insects, animals) for successful pollination.
Examples	Peas, tomatoes (some varieties can self-pollinate).	Apples, cherries, watermelons, zucchinis, where pollination often involves insects or wind.
Dependency on Agents	Not dependent on external agents; relies on gravity, structural features, or self-transfer.	Requires external agents (wind, insects, animals) for successful transfer of pollen between flowers.

FAQs – Types of Pollination

What is Pollination?

Pollination occurs when pollen grains are transferred from the anther of a flower to the stigma of the same or another flower. It is of two types self-pollination and cross-pollination.

What are the Pollinating Agents? Enlist Agents for Pollination.

Pollinating agents are the media or agents that can transfer pollen grains for pollination. Different type of pollination includes wind, water, insects, birds and animals.

Name the Plants Which Undergo Self- Pollination?

Some examples of plants that undergo self-pollination are Wheat, barley, oats, rice, tomatoes, apricots, orchids, sunflowers, peas, and peanuts.

How does Pollination Occur in Plants?

Pollination occurs when pollen from a flower’s anthers (the male part of the plant) sticks to the stigma (the female part) of another flower. The fertilized flower then produces fruit and seeds.

What are Pollen Grains?

Pollen grains are tiny, yellow, dust-like particles found inside flowers. They contain the male reproductive cells of plants.

Name the Plants which Undergo Cross Pollinations?

Some examples of plants that undergo cross-pollination are Apples, Plums, Pears, Raspberries, Blackberries, Blackcurrants, Strawberries, Runner beans.

What are the Two Main Types of Pollination?

Two main type of pollination includes self pollination and cross pollination. The main purpose of pollination is the survival and continuous reproduction of plants.

What are the 2 Parts of the Stamen?

The two parts of a stamen are the anther and supporting filament. It is the male reproductive part of the flower and produces pollen grain.