Introduction
A flowering plant’s seed is an essential component. They produce a new plant as a result of their actions. They can come in a variety of shapes, colours, and sizes. They come in a variety of shapes and sizes, including spherical, wrinkled, winged, and hairy. They will remain dormant until they acquire enough sunlight, water, and soil. The process of a plant growing from a seed is known as germination.
Structure of Seed
A seed consists of three parts:
- Seed coat
- Endosperm
- Embryo
Seed coat
The inside elements of a seed are protected by a seed coat. There are two layers to the seed coat. The testa refers to the thick outer layer. Tegmen is the name for the thin inner layer. A thick seed coat protects the seed from the light and water. It protects the seeds from losing water and parasites from entering. The tough seed coats obstruct germination in unfavourable environmental conditions.
Endosperm
The endosperm is where the nutrients are kept. It gives the seed nourishment in the form of starch, carbs, and proteins to help the embryo germinate. It can be found beneath the seed coat. The seeds can be maintained alive until they germinate by eating nutrients. Mealy, continuous, or ruminate endosperm are all possibilities. The chromosomal complement of an endosperm is triploid.
Embryo
A seed’s embryo is the most vital component. Because it was produced from a fertilised egg, it is diploid. The embryo contains all of the cells necessary for it to develop into a mature embryo. The embryo constitutes the following parts:
- Epicotyl
- Hypocotyl
- Radicle:
- Cotyledons
Types of Seeds
Seeds are of 2 types:
- Monocotyledonous seeds
- Dicotyledonous seeds
Monocotyledonous Seeds
On germination, these are made up of a single cotyledon that emerges from the seeds. Rice, for example.
Dicotyledonous Seeds
On germination, they are two cotyledons that emerge from the seeds. Take, for example, tomatoes.
Maize Seed
The caryopsis, a tiny one-seeded fruit, produces the maize grain. The seed coat (testa) of maize grain is bonded to the fruit wall (pericarp). The maize grain is golden in colour and triangular in shape on the outside. A small, opaque, oval, and whitish region on one side of the grain contains the embryo.
Structure of Maize Seed
The following structures can be seen in a longitudinal section of the seed:
Seed coat
It is made up of a thin layer that surrounds the entire grain. The seed coat and pericarp, or fruit wall, make up this layer.
Endosperm
Internally, maize grain is discovered to be split into two unequal sections by a layer called epithelium. The endosperm, which is yellowish or pale in colour, is the grain’s food storage tissue and is high in starch. However, the outermost layer, known as the aleurone layer, is made up entirely of protein. An embryo is an opaque body that resides on the other side of the endosperm, toward the pointed end.
Embryo
It is made up of a single big shield-shaped cotyledon. In the case of maize and other cereals, this is also known as scutellum. The embryo’s axis is embedded in the scutellum. The axis is made up of two parts: a plumule at the top and a radicle at the bottom. Sheath surrounds both the radicle and the plumule.
National Seeds Corporation
The National Seed Corporation (Miniratna) is a Government of India project (Miniratna) dedicated to the growth of India’s seed sector. It has a net worth of 633.62 crores and generates 1.5 lakh tonnes of seed every year. Its headquarters are in New Delhi, where it was founded in March 1963. Through its 10 Regional Offices, 8 Farms, and 65 Area Offices located over India, NSC is involved in the manufacture and distribution of quality seeds, planting materials, and the selling of Bio-Fertilizer.
Conclusion
Both biologically and economically, seeds are essential. They are abundant in protein, carbohydrate, and oil reserves, which aid in the early phases of plant growth and development. Many cereals and legumes are key food sources for a substantial proportion of the world’s population because of these reserves.