Fruit : Definition, Description, Types, Examples

Study of Fruits and seeds

Fruit:

A fruit results from maturation and fertilization of one or more flowers, and the gynoecium of the flowers forms all Or part of the fruit.

Development of fruit:

Inside the ovary/ovaries are one or more ovules where the megagametophyte contains the egg cell. After double fermentation, these ovules become seeds. The zygote gives rise to the embryo of the seed, and the endosperm mother cell gives rise to endosperm, a nutritive tissue used by the embryo.

As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the pericarp, may become fleshy(as in berries or drupes), or form a hard outer covering (as in nuts). In some multiseeded fruits, the extent to which the fresh develpos is proportional to the number of fertilized ovules.

The pericarp is differentiated into two or three distinct layers called the epicarp (outer layer, also called epicarp) mesocarp (middle layer) and endocarp (inner layer).

There are three general modes of fruit development:

1) Apocarpous fruits develpo from a single flower having one or more separate carpels, and they are the simplest fruits.

2) Syncarpous fruits develop from a single gynoecium having two or more carpels fused together.

3) Multiple fruits develop from many different flowers.

On this basis fruits are classified into three main groups as-

1) Simple fruits:

Simple fruits can be either dry or fleshy, and result from the ripening of a simple or compound ovary in a flower with only one carpel. Dry fruits may be either dehiscent (opening to discharge seeds) , or indehiscent (not opening to discharge seeds).

A) Simple, Dry, Indehiscent fruits

Achene:

The fruit develpos from polycarpellary syncarpous unilocular ovary. Pericarp and testament are very close to each other surrounding a single seed but are separable.
e. g. Mirabilis, Amaranthus.

Mirabilis

Caryopsis:

The fruit develops from bicarpellary, syncarpous, superior, unilocular ovary. Pericarp and testa are separable.
e. g. Sunflower.

Sunflower

Nut:

The fruit develops from polycarpellary, syncarpous, ovary. It has thick, hard, woody pericarp which is free from testa.
e. g. Walnut, Oaknut.

Walnut

B) Simple, Dry, Dehiscent fruits

Legume:

This fruit develops from superior monocarpellary ovary. It opens on both the sutures, dorsal and ventral and produces two values.
e. g. Beans, pea, groundnut.

Beans

Follicle:

The fruit develops from polycarpellary, partially syncarpous gynaecium. Ovaries are free each develpong into a follicle that opens along suture only forming one value.
e.g.Vinca, Nerium, Calotropis.

Vinca

Capsule:

The fruit develops from polycarpellary, syncarpous superior or inferior gynaecium. Fruit opens by several splits or pores forming many values.
e. g. Cotton, poppy, Lady's finger.

Cotton

C) Simple Fleshy fruits:

Pericarp is succulent, juicy at maturity,hence indehiscent

Drupe:

1 to 2 second;pericarp is differentiated into three layers with stony endocarp, hence called stone fruit. It has two types as-

Fleshy drupe:

It develops from polycarpellary, syncarpous, superior ovary. Outer layer of the fruit is epicarp, middle edible, fleshy is mesocarp, endocarp is hard and stony.
e. g. Mango.

Mango

Fibrous drupe:

It develops from tricarpellary, syncarpous, superior ovary. Epicarp is leathery; mesocarp is fibrous; endocarp is hard and stony. Edible part is solid and liquid endosperm.
e.g.Coconut.

Coconut

Berry:

The fruit develops from polycarpellary, syncarpous, superior or inferior, multilocular gynaecium. It is 1 to many seeded, pericarp is undifferentiated, placenata forms fresh of the fruit in which seeds are embedded.
e. g. Brinjal, Tomato, Guava.

Brinjal

Hesperidium:

Special type of berry develops from polycarpellary, syncarpous, superior or inferior, multilocular gynaecium. Here pericarp is differentiated into three layers-outer Epicarp-called as rind, Middle mesocarp-fibrous, Inner endocarp-develops into juicy, hair like sacs.

e. g. Lemon, Orange.

Lemon

Pepo:

This friut develops from inferior

inferior, tricarpellary, unilocular ovary. Pericarp undifferentiated, tough, placenta forms bulk of fresh

e. g. Cucumber, gourds.

Cucumber

Pome:

This berry develops from polycarpellary, apocarpous, superior, gynaecium. Thalamus grows and surrounds the achenes after fertilization. It forms edible portion;

hence pseudocaepic fruit.

e.g-Apple, peach.

Apple

2) Aggregate fruits:

These fruits develops from single flowers that have multiple carpels (style+stigma+ovary) which are not joined together, i.e. each pistil contains one carpel.

Etaerio of achenes:

Each achene possessess persistent hair style that helps is dispersal of fruit.

e. g. Clematis ,Strawberry.

Strawberry

Etaerio of berries:

Numerous free carpels are placed on conical thalamus that develops into one seeded berries and compact mass.

e. g. Custard apple.

Custard apple

Etaerio of drupes:

Receptacle is cup shaped and bears a number of free carpels which develops into fruitlet of drupe type.

e. g. Raspberry.

Raspberry

Etaerio of follicles:

Individual fruitlet is of follicle type. All the follicles are attached to thalamus. They dehisce by dorsal suture.

e. g. Michelia, Sterculia.

Michelia

3) Composite or multiple fruits:

Formed by fusion of several separate pistils of several grouped flowers/ inflorescence. Peduncle with accessory parts is involved in formation of fruit. Hence they are pseudocarpic fruits.

Sorosis:

In pineapple the peduncle of the spike, fertile bracts and perianth all becomes thick and fleshy at maturity. Individual fruit is of achene type.

e. g. Ananas sativus.

Ananas sativus

In jackfruit many sterile, elongated, spiny bracts in the spadix are present which produce spiny rind of the fruit. Perianths of the individual flowers are thick and fleshy which are edible.

e. g. Artocarpus.

Artocarpus

Syconus:

Hypanthodium inflorescence axis is in the form of thick, fleshy, cup shaped receptacle. Many achenes are present inside it. Receptacle is edible.

e. g. Ficus.

Ficus

*Seed-

A mature ovule consisting of an embryonic plant and a store of food, all surrounded by a seedcoat. Seed consists of seedcoat, embryo, endosperm, cotyledon.

Seedcoat:

It has two layers as testa(outer thick layer) and tegmen(inner thin membrane). It's function is protection and dispersal.

Embryo:

It is juvenile plant in the form of axis having one tip as plumule and the other tip radicle. The plumule gives rise to shoot and radical gives rise to root.

Endosperm:

It is thick, massive part of seed with starch. On the basis of presence or absence of endosperm seeds are categorized into groups as -

a) Albuminous-endosperm present

e. g. Castor, wheat, rice.