Key Difference – Autogamy vs Geitonogamy
In the context of genetics, autogamy and geitonogamy are two ways of self pollination. Autogamy is the deposition of pollen grains on the stigma of the same flower while geitonogamy is the deposition of pollen grains on the stigma of another flower of the same plant. This is the key difference between autogamy and geitonogamy.
Pollination is a method that is used for the propagation of flowering plants. Pollination is of two types namely, self pollination and cross-pollination. Autogamy and geitonogamy are two types of self pollination in the study of genetics. However, functionally, geitonogamy is a type of cross-pollination.
CONTENTS
1. Overview and Key Difference
2. What is Autogamy
3. What is Geitonogamy
4. Similarities Between Autogamy and Geitonogamy
5. Side by Side Comparison – Autogamy vs Geitonogamy in Tabular Form
6. Summary
What is Autogamy?
Autogamy is defined as a type of self pollination that is mainly observed in flowering plants, where the pollen grains of an anther of a flower are deposited on the stigma of the same flower. Autogamy occurs within the same flower. This could be further defined generally where it is a self-fertilization process facilitated by the fusion of two gametes that are derived from the same flower.
Figure 01: Autogamy
From autogamy, genetically identical offsprings are produced. Autogamy is facilitated by several adaptations that direct the deposition of mature pollen grains released from the anther on to the stigma of the same flower. It was found out that the autogamy could take place even before the flower is opened. Examples of plants that utilize this process include sunflower, orchid, peas, and tridax.
What is Geitonogamy?
Geitonogamy is defined as a type of pollination (self) in which the pollen grains of the anther of a flower get matured and deposited on the stigma of another flower of the same plant. Geitonogamy mainly occurs with the help of the presence of multiple flowers in the same plant or due to the action of pollinators.
Figure 02: Geitonogamy
With regards to function, geitonogamy could be defined as a type of cross-pollination but, in the context of genetics, it is regarded as a type of self pollination. The results of geitonogamy include the production of genetically identical offspring to the parent plant. This process is enhanced due to the presence of flowers located on a single stem.
What are the Similarities Between Autogamy and Geitonogamy?
- Both Autogamy and Geitonogamy are types of self pollination processes.
- Both take place mainly in flowering plants.
- Both result in identical offsprings to that of parents.
- Both take place within the same plant.
- Both Autogamy and Geitonogamy do not contribute to evolution since genetically identical offsprings are produced.
What is the Difference Between Autogamy and Geitonogamy?
Autogamy vs Geitonogamy |
|
| Autogamy is defined as a type of self pollination that is mainly observed in flowering plants, where the pollen grains of an anther of a flower are deposited on the stigma of the same flower. | Geitonogamy is defined as a type of pollination (self) in which the pollen grains of the anther of a flower get matured and deposited on the stigma of another flower of the same plant. |
| Pollination Type | |
| Autogamy is a type of self-pollination. | Regards to the function, geitonogamy is a type of cross-pollination, but in the context of genetics, it is a type of self pollination. |
| Adaptations | |
| In autogamy, plants are adapted to deposit pollen grains of the anther on the stigma of the same flower. This type of pollination is favoured before opening the flower. | Presence of multiple flowers on a single stem is a factor for geitonogamy. |
| Stigma Belongs to | |
| Pollen grains are deposited on the stigma of the same flower in autogamy. | Pollen grains are deposited on the stigma of another flower that of the same plant in geitonogamy. |
| Advantages | |
| No external pollinating agents are necessary for pollination in autogamy. | Maintenance of parental characteristics indefinitely is an advantage of geitonogamy. |
| Disadvantages | |
| No genetic variation is produced by autogamy. | Energy wastage on pollinator attractants is one disadvantage of geitonogamy. |
| Examples | |
| Tridax, orchids, sunflowers are pollinated by autogamy. | Plants with multiple flowers on a single stem are examples for geitonogamy. |
Summary – Autogamy vs Geitonogamy
Both autogamy and geitonogamy are self-pollination processes in the context of genetics. Autogamy involves in the deposition of pollen grains on the stigma of the same flower. Geitonogamy involves the deposition of pollen grains on the stigma of another flower of the same plant. Both processes produce genetically identical offsprings. Therefore, they do not contribute to the evolution. This is the difference between autogamy and geitonogamy.
Reference:
1.“Geitonogamy – Embibe.” Embibe: AI Powered Learning and Score Improvement Platform for Any Exam. self pollination and cross-pollination
2.“Autogamy.” Encyclopædia Britannica, Encyclopædia Britannica, Inc. Available here
Image Courtesy:
1.’Self-pollination(1)’By Jankula00 – Own work, (CC BY-SA 4.0) via Commons Wikimedia
2.’3060374’by ekamelev (Public Domain) via pixabay
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