Fruits are an essential part of plant reproduction and human nutrition. One of the key components of a fruit is the pericarp which develops from the ovary wall after fertilization. The pericarp plays a crucial role in protecting the seeds and aiding in their dispersal.
In this topic we will explore the structure types and functions of the pericarp as well as its importance in the plant life cycle.
What is the Pericarp?
The pericarp is the part of a fruit that develops from the ripened ovary wall after fertilization. It encloses and protects the seeds helping in their dispersal. The pericarp can be thin and soft like in berries or thick and hard like in nuts.
Key Functions of the Pericarp
- Protects the seeds from physical damage and predators.
- Aids in seed dispersal through wind water or animals.
- Stores nutrients that contribute to fruit development.
- Regulates water content helping in seed germination.
Structure of the Pericarp
The pericarp consists of three distinct layers:
1. Exocarp (Outer Layer)
- Also known as the fruit skin.
- Provides protection from environmental factors.
- Can be thin and soft (e.g. grapes) or thick and tough (e.g. coconut).
- May have wax hairs or pigments that attract pollinators.
2. Mesocarp (Middle Layer)
- The fleshy or fibrous part of the fruit.
- Determines the texture and taste of the fruit.
- In juicy fruits like mangoes and peaches the mesocarp is soft and edible.
- In dry fruits like almonds it is hard and inedible.
3. Endocarp (Inner Layer)
- The innermost layer surrounding the seed.
- Can be hard and stony (e.g. peaches cherries) or thin and soft (e.g. tomatoes).
- Helps in seed dispersal and protection.
Types of Fruits Based on Pericarp Structure
Fruits are classified into fleshy and dry fruits based on the texture and composition of their pericarp.
1. Fleshy Fruits
These fruits have a soft and juicy pericarp. They are commonly eaten by animals aiding in seed dispersal.
Examples of Fleshy Fruits
- Berry (e.g. tomatoes grapes) – Entire pericarp is soft.
- Drupe (e.g. mango peach) – Hard endocarp forms a pit.
- Pome (e.g. apples pears) – Fleshy mesocarp with a tough core.
2. Dry Fruits
These fruits have a dry and hardened pericarp which aids in seed protection and dispersal.
Examples of Dry Fruits
-
Dehiscent Fruits (split open to release seeds):
- Legume (e.g. peas beans) – Splits along two sides.
- Capsule (e.g. poppy cotton) – Opens in various ways.
-
Indehiscent Fruits (do not split open naturally):
- Nut (e.g. acorns walnuts) – Hard pericarp protects the seed.
- Achene (e.g. sunflower dandelion) – Small dry single-seeded fruit.
Role of the Pericarp in Seed Dispersal
The pericarp helps in dispersing seeds through different mechanisms:
- Animal Dispersal – Fleshy fruits attract animals which eat the fruit and disperse seeds.
- Wind Dispersal – Light dry fruits (e.g. dandelions) are carried by the wind.
- Water Dispersal – Floating fruits (e.g. coconuts) are carried by water.
Nutritional and Economic Importance of the Pericarp
The pericarp is nutrient-rich and has significant economic value.
1. Nutritional Benefits
- Rich in fiber aiding digestion.
- Contains antioxidants vitamins and minerals.
- Protects seeds from harmful bacteria and fungi.
2. Economic Uses
- Edible pericarps (e.g. mango banana) are major food sources.
- Spices and flavoring agents (e.g. black pepper vanilla) come from pericarp parts.
- Medicinal properties in certain fruits help in health treatments.
The pericarp is a vital part of fruit development formed from the ripened ovary wall. It plays a crucial role in seed protection dispersal and nutrition. By understanding its structure and function we can appreciate its importance in both plant reproduction and human consumption.
