Types of Polyembryony
Polyembryony can be divided into the following types:
- Induced Polyembryony: This type is induced experimentally, often in laboratory settings. It involves the controlled development of an embryo in a culture medium.
- Spontaneous Polyembryony: This occurs naturally within organisms without external intervention. Herbert John Webber, an American Plant Physiologist, further classified Spontaneous Polyembryony into three subtypes:
- Cleavage Polyembryony: Cleavage Polyembryony occurs when a young embryo or zygote separates into two or more distinct units. These units then develop into independent embryos. Sometimes, this separation results from the proliferation of the proembryo, which is the series of cells in the ovule of a flowering plant after fertilization but before the formation of the embryo. This type is more common in gymnosperms and relatively rare in angiosperms. An example is Pinus, where the zygote undergoes two divisions to produce four nuclei.
- Simple Polyembryony: Simple Polyembryony arises from the fertilization of more than one egg or from multiple archegonia, which are haploid structures producing female gametes. Pinus is also an example of Simple Polyembryony.
- Rosette Polyembryony: Rosette Polyembryony occurs when additional embryos develop from rosette cells in gymnosperms.
Polyembryony – Types, Causes, and Importance
Polyembryony refers to the occurrence of multiple embryos developing within a single ovule, seed, or fertilized ovum, and it is observed in both animals and plants. Polyembryony can be influenced by environmental conditions and genetic factors. Environmental factors such as temperature, light, and nutrient availability can cause polyembryony in certain plant species. Polyembryony examples are seen in mango, citrus, and in gymnosperms.
Genetic factors, including specific gene mutations or variations, may also play a role in regulating polyembryony. In this article, we will look into the meaning, causes, types, examples, and significance of polyembryony.
Table of Content
- What is Polyembryony in Plants?
- Causes of Polyembryony
- Types of Polyembryony
- Polyembryony in Mango
- Polyembryony in Gymnosperms
- Examples of Polyembryony
- Difference Between Apomixis and Polyembryony
- Importance of Polyembryony in Plants