Types of Pollination

Pollination in Plants

Have you ever thought about the plants, trees we see everywhere? How do these reproduce? They can't even move or in other words, these are immobile. If not, today let's learn about the reproduction in plants. The process of reproduction in plants is called pollination. The plant that undergoes pollination is called a pollinated plant. There can be different types of pollination like self-pollination and cross-pollination and these two types also have subcategories, further, we will learn about them in detail. So let's get started with understanding pollination in flowering plants also we will study about types of pollination in plants.


Pollination and its Type

The word pollination comes from pollen grains. 

Pollen grains are microscopic single-cell bodies that contain the male reproductive cell of the plants. Pollens are also called sperm cells or male gametes of the plant. Pollination occurs when pollen grains from the male part of the plant (anther) are transferred to the female part of the plant, referred to as stigma.

Before we move further we should know that flowers are the reproductive part of the plant.

After the pollen grains successfully land on the stigma a pollen tube is formed through the length of style,style is a long stalk that connects the stigma and the ovary of the flower. As the pollen tube formation gets completed the sperm cells from the pollen grain through the pollen tube are sent down to the ovary. As the sperm cell and egg cells meet, fertilisation takes place and fertilization of these cells result in formation of a seed. Later seed gets detached from the parent plant, seed grows into another plant and again in that plant occurs pollination. This way these immobile creatures reproduce through pollination. The process of 

Pollination will be more clear with the diagram below

(Image to be added soon)


Different Types of Pollination

There are basically two types of pollination one is self-pollination other is cross-pollination.

While self-pollination is the primary type of pollination, cross-pollination is a bit complex. Now we are going to study self and cross-pollination in detail.


Self-Pollination

This type of pollination deals with only one flower and hence it is quite a basic type of pollination. When pollen grain from the male part of the flower (anther) falls directly on the stigma which is the female part of the same flower and fertilisation occurs, such type of pollination is called self-pollination. The plants that undergo self-pollination are referred to as self-pollinating plants. Some examples of self-pollinating plants are: wheat, apricot, rice, peanut etc.

Self-pollination though itself is a type of pollination, it further has sub-categories as well. Let's study about them as types of self-pollination.


Types of Self-Pollination

Self-pollination can be of two types.

  1. Autogamy

  2. Geitonogamy


Autogamy

This type of self-pollination occurs where the transfer of sperm cells from the pollen grain to the stigma takes place within the same flower.

Autogamy is possible under some circumstances like

  • Both the anther and the stigma of the same flower should be open

  • Stigma should be prepared to receive the pollen when released from the anther

  • Anther and stigma should be close enough


Geitonogamy

This type of self-pollination occurs when transfer of pollen grains from the male part of the plant to the female part of the plant takes place in different flowers but of the same plant.

Geitonogamy seems more of a cross-pollination and requires pollination agent but since it occurs in the same plant is called self-pollination.


Cross-Pollination

This type of pollination is more complex as here the transfer of pollen grain occurs from the anther of one flower to the stigma of a different flower. Cross-pollination is also called xenogamy. The movement of pollen grains in cross-pollination is possible through pollinating agents. Pollinating agents can be anything like animals, insects, winds and some other abiotic and biotic things. Generally, cross-pollination occurs in bright colour flowers as their colour and odour attracts the insects like bees. Some of the cross-pollination plants are lavender, strawberry, apple, dandelion etc.


Types of Cross-Pollination

  • Pollination through biotic factors like animals, insects, birds etc.

  • Pollination through abiotic factors like wind, water etc.

Pollination through biotic factors involve the movement of pollen grains when they stick to some biotic agent like animals or bees or insects and as these agents move the stuck pollen grains get transported to another plant and fertilisation takes place.

Pollination through abiotic factors involve the movement of pollen grains when the wind blows or water is sprinkled or the rainwater spreads.

Let's have a look at wind pollination and through this, we will get to know about the pollination through other abiotic agents as well.

In wind pollination, pollination occurs through movement of pollen from the anther of one flower to stigma of other flowers by the wind. Plants that get pollinated by wind are called wind-pollinated plants.

This was all about cross & self pollination.

FAQ (Frequently Asked Questions)

1. Define Pollination and its Types.

Pollination refers to the process by which plants are able to reproduce. The pollen grains present in the anther of a flower which is the male part of the flower when land on the stigma of a flower which is a female part of the flower lead to fertilisation in the ovary. Fertilisation results in the formation of seed which gets detached from the plant and later grows into another plant and this way the reproduction of these immobile plants is possible. Pollination can basically be of two types

1) self-pollination

2) cross-pollination.

2. What are Self-pollination Types.

Self-pollination is a basic type of pollination it refers to that type of pollination in which pollen grain from anther falls directly on to the stigma of the same flower. Self-pollination requires several conditions to be fulfilled like:

  • The anther and stigma of the flower undergoing pollination should be open.

  • Anther and stigma should be close enough to each other for self-pollination to take place.

  • Stigma should be able to receive the pollen grain released by the stigma.

Type of self-pollination are:

  1. Autogamy

  2. Geitonogamy