Characteristics, advantages and disadvantages of self-pollination


Do you know the meaning of self-pollination? This article will provide you with complete information of self-pollination. You will learn the distinct characteristics of self-pollination as well as its benefits and downsides.

Introduction

The transfer of pollen grains from the anther of a flower to the stigma of the same or another flower is called pollination. In angiosperms and the most of the gymnosperms, pollination is an essential process for sexual reproduction. Pollination may be of the following two types:


Self Pollination


self pollination
(Image courtesy: www.wikipedia.com)

The transfer of pollen grains from anthers to the stigma of the same flower is known as the self-pollination. Self –pollination takes place only in case of bisexual flowers, where the anthers and stigma mature simultaneously. In such case the stigma receives the pollen grains from the same flower or different flower of the same plant. When a flower is pollinated by its own pollen, it is called autogamy as in wheat, pea, rice, etc. When pollen grains from one flower are transferred on the stigma of another flower borne on the same plant, it is called geitonogamy.

Adaptation for self-pollination

In nature self-pollination is favoured by one of the following adaptations in flower:

  1. Homogamy : Homogamy is the condition in which flowers are bisexual anther and stigma mature at the same time to make self-pollination possible. Under such a condition the stigma receives the pollen grains from the anthers of the same flower by the agency of wind or insects. E.g., Mirabilis, Ixora, Sunflower, etc.

  2. Cleistogamy : There are some bisexual flowers, which never open. They are small and sometimes inconspicuous and remain closed. The pollen grains, therefore, may only pollinate on the stigma of the same flower. Such a condition is called cleistogamy and the flower are called cleistogamous flowers. E.g., Commelina benghalensis, Impatiens (Balsam), Arachis hypogea (Groundnut), etc.

Characteristics of self-pollinated flowers

The characteristics of self-pollinated flower or plants are given below:

  • Self-pollination occurs between anther and pistils of the same flower or different flowers of the same plant.

  • Presence of bisexual flower or monoecious plants are must for self-pollination.

  • Flowers are generally small, less attractive and without nectar.

  • Less number of pollen grains are required.

  • Seed Produced through self-pollination are small, light in weight and less in number.

  • Progenies of self-breeding plants exhibit less vigour. Sometimes they are weak.

  • Newer qualities other than parents never develop.

  • Progenies show almost nil variation which is essential for evolution.

  • Plants produced show genetical purity.

  • Self-pollination increases homozygosity among plants.

  • Chances of pollination is 100 percent in self-pollinated plants.



Advantages of self-pollination

The main advantages of self-pollination are as below:

  • A very few pollen grain can pollinate the flower.

  • Purity of the race is maintained.

  • Self-pollination avoid wastage of pollen grains.

  • Less chances of failure of pollination.


Last words

As you have seen there are many advantages of self-pollination and there is no need for any medium, there are still some disadvantages of self-pollination which are given below:

  • Self-pollinated flowers have small, light weighted and fewer numbers of seeds.

  • Continuous self-pollination results in the production of weaker progeny.

  • there are no chances of the production of new species and varieties of plants.

  • The chances of evolution is also reduced.

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