The key difference between apospory and apogamy is that in apospory, the gametophyte develops directly from the 2n sporophyte, while in apogamy, the embryo develops without undergoing fertilization.
Apospory and apogamy are two types of asexual reproduction processes taking place in plants. Therefore, in both processes, the formation of gametes and syngamy do not take place. However, these two processes could lead to the alteration of sexual reproduction in plants. Both processes are predominantly present in bryophytes.
CONTENTS
1. Overview and Key Difference
2. What is Apospory
3. What is Apogamy
4. Similarities Between Apospory and Apogamy
5. Side by Side Comparison – Apospory vs Apogamy in Tabular Form
6. Summary
What is Apospory?
Apospory refers to the development of gametophyte directly from the cell of sporophyte without spore formation or meiosis. The sporophyte is present in the vegetative cells of the plant. Therefore, when the gametophyte forms, the sporophytic generation marks its end. Moreover, this is important in the alternation of generations in plants.
Figure 01: Apospory
Since the cells of sporophyte are diploid, the developed gametophyte is also diploid in nature. Thus, the sporophyte and gametophyte share the same ploidy levels. However, this process does not involve the formation of gamete cells. So, it is asexual in nature. Apospory is an asexual reproduction method commonly seen in bryophytes.
What is Apogamy?
Apogamy refers to an asexual reproduction process in plants where the embryo forms without undergoing fertilization. In such plants, sporophyte develops from the gametophyte without undergoing fertilization. Thus, the formed sporophyte will have the same ploidy level of the gametophyte.
Figure 02: Apogamy
Moreover, this process takes place both in flowering and non-flowering plants such as bryophytes.
What are the Similarities Between Apospory and Apogamy?
- Apospory and apogamy are asexual methods of reproduction.
- Both take place in plants.
- They participate in the alternation of generations in plants.
- In both phenomena, the gametophyte and the sporophyte share the same ploidy level.
- Moreover, there is no formation of gametes in both processes.
- Both these processes mainly take place in bryophytes.
What is the Difference Between Apogamy and Apospory?
Although both apogamy and apospory are asexual processes of reproduction in plants, they have differences in their development process. During apospory, the gametophyte develops from the sporophyte, while in apogamy, the embryo develops without fertilization. So, this is the key difference between apospory and apogamy.
Moreover, another difference between apospory and apogamy is their ploidy levels. In apogamy, it forms a diploid gametophyte whereas, in apospory, it forms a haploid embryo.
Summary – Apogamy vs Apospory
Asexual reproduction is the form of reproduction that does not involve gametes. In this regard, apogamy and apospory refer to two asexual modes of reproduction in plants such as bryophytes. Apospory refers to the production of a diploid gametophyte from a diploid sporophyte. In contrast, apogamy refers to the process of developing a haploid embryo without fertilization. Therefore, these two processes are important in the alternation of generations in plants. These are special adaptations shown by low-level plants for their survival. Thus, this is the summary of the difference between apospory and apogamy.
Reference:
1. “Apospory.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., Available here.
2. “Significance of Homospory, Apospory and Apogamy.” GulpMatrix, 29 Sept. 2018, Available here.
Image Courtesy:
1. “Anthoceros agrestis 060910d” By BerndH – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Funaria Moss” By Jayesh Patil (CC BY 2.0) via Flickr