Difference Between Parthenocarpy and Parthenogenesis

The main difference between parthenocarpy and parthenogenesis is that the parthenocarpy is the formation of fruit from an unfertilized ovule in plants whereas parthenogenesis is the development of an unfertilized ovum into a new individual in animals. Furthermore, the fruit developed by parthenogenesis does not contain seeds while the individuals developed from parthenogenesis are mainly haploid and incapable of reproducing sexually. 

Parthenocarpy and parthenogenesis are two alternative methods of reproduction that do not undergo fertilization. In both methods, gametes are produced. 

Key Areas Covered 

1. What is Parthenocarpy
     – Definition, Types, Examples
2. What is Parthenogenesis
     – Definition, Facts, Examples
3. What are the Similarities Between Parthenocarpy and Parthenogenesis
     – Outline of Common Features
4. What is the Difference Between Parthenocarpy and Parthenogenesis
     – Comparison of Key Differences

Key Terms 

Apomixis, Haploid, Parthenocarpy, Parthenogenesis, Seedless Fruit, Sexual Reproduction, Stenospermocarpy

What is Parthenocarpy 

Parthenocarpy is the development of unfertilized ovule into a fruit. Since the ovule is unfertilized, these types of fruits are known as ‘virgin fruits’. Moreover, parthenocarpic fruits are seedless. Parthenocarpy naturally occurs in some fruits such as banana, pineapple, watermelon, and apple. Natural parthenocarpy can be caused by mutation. Stenospermocarpy is another form of parthenocarpy. During this, the fertilized eggs are aborted when they are small in order to produce a seedless fruit. Artificial parthenocarpy increases the quality and the productivity of the fruit. 

Figure 1: Parthenocarpic Watermelon

In parthenocarpy, the ovule can be induced even without pollination to produce a fruit. This type of parthenocarpy is called vegetative parthenocarpy. In contrast, the type of parthenocarpy that is stimulated with pollination is called stimulative parthenocarpy.  

What is Parthenogenesis 

Parthenogenesis is the development of a new individual from an unfertilized ovum. It mainly occurs in animals such as lizards and insects such as bees, wasps, ants, aphids, rotifers, etc. It sometimes occurs in lower plants as well. Parthenogenesis in higher plants is called apomixis. But, parthenogenesis does not occur in higher animals. 

Figure 2: C. inornatus (left), C. neomexicanus (center, undergo parthenogenesis), C. tigris (right)

Since the unfertilized egg develops into a new individual, the offspring of parthenogenesis is mainly haploid and is incapable of undergoing sexual reproduction. In rare cases, diploid organisms can be produced by pairing the two chromosome sets of the mother organism. Thus, these individuals can switch between sexual reproduction or parthenogenesis. 

Similarities Between Parthenocarpy and Parthenogenesis 

• Parthenocarpy and parthenogenesis are two alternative methods of reproduction that involve the formation of gametes. 
• Neither methods undergo fertilization of gametes. 
• Therefore, both can be considered as unisexual reproduction methods. 

Difference Between Parthenocarpy and Parthenogenesis 

Definition 

Parthenocarpy refers to the development of a fruit without prior fertilization while parthenogenesis refers to reproduction from an ovum without fertilization, especially as a normal process in some invertebrates and lower plants. 

Significance 

The fruit produced through parthenocarpy does not contain seeds while the individuals produced through parthenogenesis are mostly haploid and unable to reproduce sexually. This is one main difference between parthenocarpy and parthenogenesis.

Production of an Offspring 

Furthermore, parthenocarpy does not produce an offspring while parthenogenesis produces a haploid offspring. 

Occurrence 

Parthenocarpy occurs in plants such as watermelon, banana, pineapple, and roses while parthenogenesis occurs in lizards and insects. 

Conclusion 

Parthenocarpy is the production of a fruit without seeds through prevailing fertilization of the ovule. But, parthenogenesis is the development of a new individual from an unfertilized ovum. Parthenocarpy mainly occurs in plants while parthenogenesis mainly occurs in animals. The main difference between parthenocarpy and parthenogenesis is the type of reproduction. 

Reference:

1. Grant, Bonnie L. “What Is Parthenocarpy: Information And Examples Of Parthenocarpy.” Gardening Know How, Available Here
2. Mittwoch, U. “Parthenogenesis.” Journal of Medical Genetics 15.3 (1978): 165–181. Available Here

Image Courtesy:

1. “Watermelon seedless” By Scott Ehardt – Own work (Public Domain) via Commons Wikimedia    
2. “Cnemidophorus-ThreeSpecies” By Alistair J. Cullum (Acullum at en.wikipedia) Email: [email protected] – Transferred from en.wikipedia to Commons by Innotata using CommonsHelper via Commons Wikimedia