Introduction
Edible fruits in particular have long propagated using the movements of humans and animals in a symbiotic relationship that is the means for seed dispersal for one group and nutrition for the other; in fact, humans and many animals have become dependent on fruits as a source of food. If the fruit is formed without fertilisation of the ovary, it is known as parthenocarpic fruit, e.g., banana.
Fruits are an important source of vitamins, minerals and fibres and are thus considered natural medicines. They are also an essential source of a balanced diet. Some fruits contain seeds within them, while others are seedless.
Parts of a fruit
The fruit mainly consists of two parts: the pericarp and the seed. The pericarp layer is the outer wall of the ovary from which the fruit develops. The pericarp further has three layers:
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Exocarp or Epicarp:
When the pericarp is thick and fleshy, its outer layer is known as the epicarp. It forms the skin of a fruit. Epicarp protects the inner parts of the fruit from damage. In citrus fruits, the epicarp layer is referred to as flavedo.
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Mesocarp:
The middle, thick, fleshy and juicy layer of the pericarp, is seen in apples, mangoes, and peaches. The white mesocarp layer after the flavedo in citrus fruits is referred to as albedo.
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Endocarp:
It is the innermost layer of the pericarp, which frequently develops into a pith. It immediately surrounds the seed. It protects the seed from damage. Endocarp is usually not consumed, while in citrus fruits like oranges, it forms the central juicy, edible part.
Type of fruits
Based at the wide variety of ovaries and the wide variety of flowers concerned within the fruit formation, fruits are categorised into 3 primary groups namely:
1. Simple Fruits: These fruits evolve from one matured ovary in a single flower. Apple, banana, cherry pear, plum and tomato are a few examples of simple fruits. The simple fruits are categorised into the subsequent categories:
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Drupes: These also are called stone fruits because they include a very hard seed within the simple fruits. For eg., plum, cherry, peach
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Berries: These sort of fruits have one seed within the middle and are very juicy. For eg., grapes, blueberries
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Pomes: Such fruits have their flowers in trees. For eg., apple, papaya
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Hesperidium and Pepos: They are barely just like the berries and consist of fruits like watermelon, citrus fruits, etc.
2. Aggregate Fruits: These fruits evolve from some of the matured ovaries produced in a flower. Individual ovaries are called “fruitlets”. For example Blackberry, raspberry, strawberry, etc.
3. Composite Fruits: These fruits evolve from an entire inflorescence. Those also are referred to as multiple fruits. There are two types of Composite fruits:
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Sorosis: These are determined in mulberry, jackfruits and pineapple. They evolve from catkin, spikes and spadix forms of inflorescence
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Syconus: This develops from hypanthodium form of inflorescence
Significance of Fruit Formation
Fruits have been in use since the prehistoric times as the main food of man. Even today fruits comprise the main part of the human diet.
Further, fruit formation has its own significance for the plant:
1. Fruit helps to protect the immature seeds from unfavourable environmental conditions. The seeds remain within the fruit until they are ready to germinate.
2. The colour of the fruit wall also helps in protection of seeds. When young, most of the fruits are green and remain hidden in the foliage.
3. The immature fruits offer chemical defence against the animals because they contain unpalatable and repelling substances like astringents, tannins, sour acids and bitter alkaloids.
4. Mature fruits acquire bright colours to attract seed-dispersing animals.
Economic Importance of Fruits
1. Fruits are an important item of our diet.
2. Cereals, the one-seeded dry fruits, constitute the staple food of man.
3. A large number of fruits like Cucumber, Lady’s finger, Tomato, Pumpkin, etc., are used as vegetables.
4. Fruits are a source of vitamins, minerals, organic acids, pectin, sugar, etc.
Conclusion
Fruit is a mature, ripened ovary. The two main functions of fruit are to prevent. The seeds from drying and dispersed the seed.
Three major divisions include simple fruits, aggregate fruits, and multiple fruits. Simple fruits are defined as having developed from a single ovary of a single pistil.
Simple fruits may be fleshy or dry. Fleshy fruit includes berries, pepo, drupes, and pomes. Dry fruits may be indehiscent or dehiscent. Aggregate fruits develop from a Single flower that has many pistils. Multiple fruits consist of a number of flowers that fused to form a mass.
Three major parts of the pericarp are the exocarp, mesocarp, and endocarp.
The process of fruit development is dictated by plant hormones. Seedless fruits can develop by parthenocarpy.