Introduction
There are many plants where the fruits are developed without any kind of fertilization, such as bananas, oranges etc. The process where the fruit is developed without any kind of fertilization is called parthenocarpy. Fertilization can be failed because of many reasons such as the quality and quantity of the gametes or the reason can be the environment surrounding the gamete. However, when fertilization does not occur or completely failed, the plant depends on asexual reproduction.
What is Apogamy?
Apogamy is one kind of asexual reproduction, where the gametophyte generation gets replaced by the sporophyte. This total process is also known as the replacement of the sexual phase by the asexual phase. It is also known as the spore of one hundred fathers because the mature form of the spore is produced without any kind of fertilization. In simple words, apogamy is a result of the failed fertilization process.
Apogamy is commonly found in ferns and this process, the haploid sporophyte is developed from the haploid gametophyte, which occurs without any kind of fusion of gametes. This type of asexual reproduction was first named in the year 1878, by Heinrich Anton de Bary.
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Causes of Apogamy
There are many causes for apogamy.
- It occurs in those plants, where prothallus is aged, and it increases the chance of apogamy.
- This process occurs without the fusion, means when the gametes are not produced by the gametophyte. The chances of apogamy are higher in those situations when the total process of sex organ formation fails.
- Sometimes plants cannot go through the common process of fertilization, which means sexual reproduction. The reason can be either the physical condition or it can get affected by the environment.
- In high temperatures when there is a lack of nutrition and water, plants choose apogamy over sexual reproduction.
What is Apospory?
Apospory is one kind of asexual reproduction, where the sporophyte can develop from the gametophyte. This process occurs without any kind of fertilization process. In this type of reproduction process the diploid gametophyte forms with the help of vegetative cells, and most importantly there is no meiosis and spores’ formation. This process was first discovered in the year 1884 and named by Druery.
Causes of Apospory
There are many for the occurrence of apospory.
- This type of asexual reproduction occurs when there is no chance of fertilization.
- If there is a lack of minerals and nutrients in the soil, pteridophytes perform this type of reproduction process
- When the leaves are developed under low light the chance of apospory increases.
- The main reason behind this is the lack of chances for sexual reproduction.
Similarities between Apogamy and Apospory
There are many differences between these two types of asexual reproduction. However, there are some similarities too.
- In the case of apogamy and apospory, the process of reproduction is asexual.
- These two types of reproduction processes occur in plants.
- In both cases, gamete formation does not occur.
- In these two cases, gametophyte and sporophyte share the same ploidy level.
- It occurs mainly in the bryophytes.
- They both are the alternative version of sexual reproduction.
- With the help of hormones, these two types of reproduction processes can be performed in the laboratory.
- Any kind of hormones is not necessary for both apogamy and apospory.
Difference between Apogamy and Apospory
| Apogamy | Apospory |
|---|---|
| The term Apogany is named by Heinrich Anton de Bary | The term Apospory is given by Druery. |
| It involves gametophytic cells, such as antipodal and synergids. | It involves sporophytic cells such as nucellar cells. |
| This type of asexual reproduction is visible in ferns. | This type of asexual reproduction is common in the vegetative cells of plants. |
| There is no fusion of gametes, which indicates that it occurs without fertilization. | It occurs without the formation of meiosis or spores. |
| It occurs without any kind of syngamy. | It occurs without any kind of sporadic meiosis. |
| The haploid gametophyte does not develop in the diploid sporophyte, rather it forms in the haploid sporophyte. | The diploid sporophyte does not develop in the haploid gametophyte, rather it develops in the diploid sporophyte. |
| This kind of reproduction process can be found in the funaria. | This kind of reproduction process can be found in Anthoceros. |