Plant growth and movement
• Growth is a process in which there is increase in the size by cell division and
enlargement accompanied by the formation of new cellular material. It
results in the irreversible increase in size, length area or volume accompanied
by increase in dry weight.
• The growth is followed by the development. The term development in plant
includes all the changes that an organism goes through during its life cycle
from germination of the seed to senescence.
Seed germination
• Seed germination may be defined as the fundamental process by which
different plant species grow from a single seed into a plant. This
process influences both crop yield and quality.
• Process of seed germination:
• During the beginning stage of germination, the seeds take up water rapidly
and this results in swelling and softening of the seed coat at an optimum
temperature. This stage is referred to as Imbibition. It starts the growth
process by activation of enzymes. The seed activates its internal physiology
and starts to respire and produce proteins and metabolizes the stored food.
This is a lag phase of seed germination.
, Seed germination
• By rupturing of the seed coat, radicle emerges to form a primary root. The
seed starts absorbing underground water. After the emerging of the
radicle and the plumule, shoot starts growing upwards.
• In the final stage of seed germination, the cell of the seeds become
metabolically active, elongates and divides to give rise to the seedling
• Types of seed germination
a. Epigeal Germination:
• In this type of germination, the hypocotyl elongates rapidly and arches
upwards pulling the cotyledons which move above the soil. Bean, cotton,
papaya, gourd, castor and onion have germination of this kind.
• b. Hypogeal germination:
• In this type of germination, the epicotyl elongates and the cotyledons
remain below the soil. Pea, mango, maize, rice, gram and groundnut have
germination of this kind.
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• Growth is a process in which there is increase in the size by cell division and
enlargement accompanied by the formation of new cellular material. It
results in the irreversible increase in size, length area or volume accompanied
by increase in dry weight.
• The growth is followed by the development. The term development in plant
includes all the changes that an organism goes through during its life cycle
from germination of the seed to senescence.
Seed germination
• Seed germination may be defined as the fundamental process by which
different plant species grow from a single seed into a plant. This
process influences both crop yield and quality.
• Process of seed germination:
• During the beginning stage of germination, the seeds take up water rapidly
and this results in swelling and softening of the seed coat at an optimum
temperature. This stage is referred to as Imbibition. It starts the growth
process by activation of enzymes. The seed activates its internal physiology
and starts to respire and produce proteins and metabolizes the stored food.
This is a lag phase of seed germination.
, Seed germination
• By rupturing of the seed coat, radicle emerges to form a primary root. The
seed starts absorbing underground water. After the emerging of the
radicle and the plumule, shoot starts growing upwards.
• In the final stage of seed germination, the cell of the seeds become
metabolically active, elongates and divides to give rise to the seedling
• Types of seed germination
a. Epigeal Germination:
• In this type of germination, the hypocotyl elongates rapidly and arches
upwards pulling the cotyledons which move above the soil. Bean, cotton,
papaya, gourd, castor and onion have germination of this kind.
• b. Hypogeal germination:
• In this type of germination, the epicotyl elongates and the cotyledons
remain below the soil. Pea, mango, maize, rice, gram and groundnut have
germination of this kind.
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