What is the Difference Between Apospory and Apogamy

The main difference between apospory and apogamy is that apospory is the development of a gametophyte directly from the sporophyte without undergoing either meiosis or spore formation whereas apogamy is the development of an embryo without fertilization. Furthermore, apospory occurs in Anthoceros while apogamy occurs in Funaria.

Apospory and apogamy are two terms that describe methods of asexual reproduction which alter the usual sexual reproduction of plants.

Key Areas Covered

1. What is Apospory
     – Definition, Features, Importance
2. What is Apogamy
     – Definition, Features, Importance
3. What are the Similarities Between Apospory and Apogamy
     – Outline of Common features
4. What is the Difference Between Apospory and Apogamy
     – Comparison of Key Differences

Key Terms

Apogamy, Apospory, Asexual Reproduction, Embryo, Gametophyte, Sporophyte

What is Apospory

Apospory is the development of a gametophyte from the vegetative cells of the sporophyte without undergoing spore formation or meiosis. Thus, the forming gametophyte is diploid or has the same ploidy level with the sporophyte.

Figure 1: Anthoceros

What is Apogamy

Apogamy is the formation of an embryo without undergoing fertilization. Generally, the term ‘apogamy’ is used to describe the apomixis of plants with an individual gametophyte, especially in ferns. In bryophytes, a group of cells of the gametophyte similar to an embryo develops into the sporophyte of the species. 

Figure 2: Apomixis

Similarly, the sporophyte produced by apogamy has the same ploidy level of the gametophyte. However, apomixis is the term that describes the formation of an embryo without undergoing fertilization, mainly in flowering plants.

Similarities Between Apospory and Apogamy

• Apospory and apogamy are two methods of asexual reproduction altering the usual sexual reproduction in plants.
• In both methods, the sporophyte produces different types of reproductive units without undergoing meiosis.
• Therefore, there is no production of gametes.
• Also, these two methods mainly occur in bryophytes and less commonly ferns and lycopods.

Difference Between Apospory and Apogamy

Definition

Apospory refers to the development of 2n gametophytes, without meiosis and spores, from vegetative, or nonreproductive, cells of the sporophyte, while apogamy refers to a type of reproduction, occurring in some ferns, in which the sporophyte develops from the gametophyte without fusion of gametes.

Significance

The main difference between apospory and apogamy is that apospory is the production of a gametophyte without the production of spores while apogamy is the formation of an embryo without undergoing fertilization.

Ploidy

Furthermore, while apospory produces a diploid gametophyte, apogamy produces a haploid embryo. Hence, this is also a difference between apospory and apogamy.

Occurrence

Also, another difference between apospory and apogamy is that apospory occurs in Anthoceros while apogamy occurs in Funaria.

Conclusion

Apospory is the production of a gametophyte by the sporophyte without undergoing meiosis or formation of spores. As there is no meiosis in apospory, the gametophyte is diploid. In contrast, apogamy is the formation of an embryo without undergoing fertilization. Therefore, the forming sporophyte from the embryo is always haploid. Both apospory and apogamy are two types of asexual reproduction methods which alter the regular sexual reproduction. However, the main difference between apospory and apogamy is the type of reproductive structure produced in each process and their ploidy.

References:

1. “Apomixis.” Wikipedia, Wikimedia Foundation, 14 Feb. 2019, Available Here.

Image Courtesy:

1. “Anthoceros agrestis 060910c” By BerndH – Own work (CC BY-SA 3.0) via Commons Wikimedia  
2. “Poa bulbosa, vegetative apomixis” By Nadiatalent – Own work (CC BY-SA 3.0) via Commons Wikimedia