Seed

Seed

Do all fruits contain seeds? No, triploid fruits do not. The seed is a fertilized mature ovule which possess an embryonic plant, usually stores food material and has a protective coat. After fertilization, changes occur in various parts of the ovule and transforms into a seed.

Types of Seed

Do seeds germinate as soon as they are dispersed

I.         Based on the number of cotyledons present two types of seeds are recognized.

i.          Dicotyledonous seed: Seed with two cotyledons.

ii.        Monocotyledonous seed: Seed with one cotyledon.

II.      Based on the presence or absence of the endosperm the seed is of two types.

i. Albuminous or Endospermous seed: The cotyledons are thin, membranous and mature seeds have endosperm persistent and nourishes the seedling during its early development. Example: Castor, sunflower, maize.

ii.        Ex-albuminous or non-endospermous seed: Food is utilized by the developing embryo and so the mature seeds are without endosperm. In such seeds, colyledons store food and become thick and fleshy. Example: Pea, Groundnut.

Significance of Seeds:

v  The seed encloses and protects the embryo for next generation.

v  It contains food for the development of embryo.

v  It is a means for the dispersal of new individuals of the species.

v  A seed is a means for perpetuation of the species. It may lie dormant during unfavorable conditions but germinates on getting suitable conditions.

v  Seeds of various plants are used as food, both for animals and men.

v  They are the basis of agriculture.

v  Seeds are the products of sexual reproduction so they provide genetic variations and recombination in a plant.