Seeds and sowing – Seed Germination
Seed Germination: Means the resumption of growth by embryo & development of a young seedling from the seed. Germination is an activation of dormant embryo to give rise to radical (root development) and plumule (stem development).Germination is the awakening of the dormant embryo. The proce4ss by which the dormant embryo wakes up & begins to grow is known as Germination.
Seed Emergence Means actually coming above and out of the soil surface by the seedling.
Changes During Germination:
1) Swelling of seed due to imbibition of water by osmosis.
2) Initiation of physiological activities such as respiration & secretion of enzyme.
3) Digestion of stored food by enzymes.
4) Translocation & assimilation of soluble food.
When seed is placed in soil gets favorable conditions, radical grows vigorously & comes out through micro Pyle & fixes seed in the soil. Then either hypo or epicotyls begins to grow.
Types of germination:
1. Hypogeal germination: The cotyledons remain under the soil. E.g.: cereals, gram.
2. Epigeal germination: The cotyledons pushed above the soil surface. E.g.: mustard, tamarind, sunflower, castor, onion.