Fruit
A fruit is a mature or ripened ovary containing seeds, developed after fertilisation.
True fruit:
If a fruit is formed only from the ovary, it is called true fruit or eucarp.
The wall of a true fruit is called pericarp. The pericarp may be thick, fleshy and juicy or it may be papery or leathery.
Pericarp differentiates into three regions:
(i) Epicarp: forms the outer skin.
(ii) Mesocarp: forms the edible, fleshy region.
(iii) Endocarp: forms the innermost hard region that encloses the seed.
Ex: Mango, Tomato
False fruit:
If any part of the flower other than ovary forms the edible part, the fruit is called a false fruit or pseudocarp.
Ex: Apple, Strawberry
Parthenocarpic fruit:
If a fruit develops without fertilisation of the ovary, it is called a parthenocarpic fruit. These are generally seedless or have non-viable seeds.
Ex: Banana, Grapes
Pomology is the branch of horticulture that deals with the study of fruits and their cultivation.
Drupe
It develops from a monocarpellary or multicarpellary, syncarpous ovary.
The pericarp is differentiated into outer epicarp, middle mesocarp and inner endocarp.
The endocarp is hard and hence these fruits are also known as stone fruits.
Normally they enclose a single seed.
Ex: Mango, Coconut
Seed
A seed is a fertilised and mature ovule.
The outer integument of the ovule forms the outer layer of seed coat, called testa.
The inner integument of the ovule forms the inner layer of seed coat, called tegmen.
Generally, the testa and tegmen are completely fused, but in bean, they are distinct.
A seed which contains the endosperm, is called endospermic/albuminous seed.
A seed which does not contain the endosperm, is called non-endospermic/exalbuminous seed.
Rarely, the nucellus remains in a seed and such a remnant of the nucellus is called perisperm.
A seed which has only one cotyledon, is called monocotyledonous seed.
A seed which has two cotyledons, is called dicotyledonous seed.
Structure of Dicotyledonous Seed
Dicotyledonous seed consists of,
(i) Seed coat with testa, tegmen, hilum, micropyle and raphae.
(ii) Embryo with two cotyledons and embryonal axis.
The seed is attached to the fruit wall by a short stalk, called funiculus.
When the seed is separated from the fruit, the funiculus leaves a scar on the seed, called hilum.
Just below the hilum,there is a small opening on the seed coat, called micropyle, through which water enters the seed during germination.
Hilum and micropyle, both are present on raphae, through which food is supplied to the embryo.
The outer seed coat, called testa, is thick, smooth and variously coloured.
The inner seed coat, called tegmen, is thin and white, and is often fused with the testa.
Fleshy Emryo is present, well protected by the seed coat. It consists of two cotyledons that store food material. And a short embryonal axis to which cotyledons are attached.
Embryonal axis has two parts, the radicle and plumule.
Radicle: On germination it gives rise to the root system.
Plumule: On germination it gives rise to the shoot system.
Endospermous dicot seeds: In some seeds, the endosperm is formed as a result of double fertilisation. It is a food storing tissue.e.g. Castor
Non-endospermous dicot seeds: The endosperm is not present in the mature seed. e.g. Gram
Structure of Monocotyledonous Seed
Monocotyledonous seed consists of,
(i) Seed coat
(ii) Endosperm
(iii) Embryo with embryonal axis and cotyledon
The fruit wall and the seed coat are completely fused to form the husk.
Inside the major portion is endosperm which stores food in the form of starch.
Endosperm is covered by a layer of cells containing proteins called aleurone layer, which separates it from the embryo.
Embryo is obliquely on the lower side of endosperm. It consists of,
(i) Cotyledon: Single, shield shaped much reduced cotyledon, called scutellum, which is attached laterally on one side to the embryonal axis.
(ii) Radicle: The region of the embryonal axis that points downward from the point of attachment of cotyledon is the radicle, which is surrounded and protected by a root sheath called the coleorhiza.
(iii) Plumule: The region of the embryonal axis that points upward from the point of attachment of cotyledon is the plumule, which is surrounded and protected by a root sheath called the coleoptile.
Most of the monocotyledonous seeds are endospermic or albuminous, but there are a few non-endospermic or exalbuminous seed such as Orchids.
A fruit is a mature or ripened ovary containing seeds, developed after fertilisation.
True fruit:
If a fruit is formed only from the ovary, it is called true fruit or eucarp.
The wall of a true fruit is called pericarp. The pericarp may be thick, fleshy and juicy or it may be papery or leathery.
Pericarp differentiates into three regions:
(i) Epicarp: forms the outer skin.
(ii) Mesocarp: forms the edible, fleshy region.
(iii) Endocarp: forms the innermost hard region that encloses the seed.
Ex: Mango, Tomato
False fruit:
If any part of the flower other than ovary forms the edible part, the fruit is called a false fruit or pseudocarp.
Ex: Apple, Strawberry
Parthenocarpic fruit:
If a fruit develops without fertilisation of the ovary, it is called a parthenocarpic fruit. These are generally seedless or have non-viable seeds.
Ex: Banana, Grapes
Pomology is the branch of horticulture that deals with the study of fruits and their cultivation.
Drupe
It develops from a monocarpellary or multicarpellary, syncarpous ovary.
The pericarp is differentiated into outer epicarp, middle mesocarp and inner endocarp.
The endocarp is hard and hence these fruits are also known as stone fruits.
Normally they enclose a single seed.
Ex: Mango, Coconut
Seed
A seed is a fertilised and mature ovule.
The outer integument of the ovule forms the outer layer of seed coat, called testa.
The inner integument of the ovule forms the inner layer of seed coat, called tegmen.
Generally, the testa and tegmen are completely fused, but in bean, they are distinct.
A seed which contains the endosperm, is called endospermic/albuminous seed.
A seed which does not contain the endosperm, is called non-endospermic/exalbuminous seed.
Rarely, the nucellus remains in a seed and such a remnant of the nucellus is called perisperm.
A seed which has only one cotyledon, is called monocotyledonous seed.
A seed which has two cotyledons, is called dicotyledonous seed.
Structure of Dicotyledonous Seed
Dicotyledonous seed consists of,
(i) Seed coat with testa, tegmen, hilum, micropyle and raphae.
(ii) Embryo with two cotyledons and embryonal axis.
The seed is attached to the fruit wall by a short stalk, called funiculus.
When the seed is separated from the fruit, the funiculus leaves a scar on the seed, called hilum.
Just below the hilum,there is a small opening on the seed coat, called micropyle, through which water enters the seed during germination.
Hilum and micropyle, both are present on raphae, through which food is supplied to the embryo.
The outer seed coat, called testa, is thick, smooth and variously coloured.
The inner seed coat, called tegmen, is thin and white, and is often fused with the testa.
Fleshy Emryo is present, well protected by the seed coat. It consists of two cotyledons that store food material. And a short embryonal axis to which cotyledons are attached.
Embryonal axis has two parts, the radicle and plumule.
Radicle: On germination it gives rise to the root system.
Plumule: On germination it gives rise to the shoot system.
Non-endospermous dicot seeds: The endosperm is not present in the mature seed. e.g. Gram
Structure of Monocotyledonous Seed
Monocotyledonous seed consists of,
(i) Seed coat
(ii) Endosperm
(iii) Embryo with embryonal axis and cotyledon
The fruit wall and the seed coat are completely fused to form the husk.
Inside the major portion is endosperm which stores food in the form of starch.
Endosperm is covered by a layer of cells containing proteins called aleurone layer, which separates it from the embryo.
Embryo is obliquely on the lower side of endosperm. It consists of,
(i) Cotyledon: Single, shield shaped much reduced cotyledon, called scutellum, which is attached laterally on one side to the embryonal axis.
(ii) Radicle: The region of the embryonal axis that points downward from the point of attachment of cotyledon is the radicle, which is surrounded and protected by a root sheath called the coleorhiza.
(iii) Plumule: The region of the embryonal axis that points upward from the point of attachment of cotyledon is the plumule, which is surrounded and protected by a root sheath called the coleoptile.
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