Seed Development, Structure, and Germination in Plants

Doomsday Vault

Seed Bank

Seed

Develops from the fertilized ovule and includes the embryo and endosperm within a seed coat.

Double fertilization

Yields a diploid zygote (embryo) and a triploid central nuclei (endosperm).

Endosperm Development

Usually develops first before the embryo.

Central nuclei

Divides to form a multinucleate 'supercell' with a milky consistency.

Coconut 'milk'

Example of liquid endosperm.

Coconut 'meat'

Example of solid endosperm.

Monocot Endosperms

The endosperm of grains such as corn, wheat, and rice occupies the bulk of the kernel and is the main energy reserve for the development of the young seedling.

Monocot

Stores the bulk of its energy in the endosperm.

Dicot Endosperms

Most dicot seeds lack endosperms upon maturity.

Food reserves of the endosperm

Are completely transferred to the embryo in dicots.

Dicot

Stores its food in the two cotyledons.

Seed Structure

Includes embryo, endosperm, seed coat, radicle, epicotyl, hypocotyl, and cotyledon.

Embryo

Young plant.

Endosperm

Stored food for embryo.

Seed coat

Encases the seed.

Radicle

Embryonic root.

Epicotyl

Embryonic shoot.

Hypocotyl

Junction between roots and shoots.

Cotyledon

Seed leaf.

Embryogenesis

Zygote undergoes mitotic division and gives rise to terminal and basal cell.

Suspensor

Helps in transferring nutrients to the embryo.

Seed Dormancy

A survival mechanism by which seeds can delay germination until the right environmental conditions for seedling growth and development.

Germination for Dicot

The first organ to emerge is the radicle.

Germination for Monocot

Shoot tip grows through the coleoptile (sheath) once it has pushed through the surface of the soil.