Download Seed Characteristics

Seed Characteristics
Plant Propagation
3 Basic Parts
 Embryo
 Food
Storage Tissues
 Coverings
Embryo
 Living
part of the seed.
 Produced by the fusion of male and
female gametes.
Young Seedling

Epicotyl: means
“above the
cotyledons”. It
becomes the
above-ground
shoot.
 Hypocotyl: means
“below the
cotyledons”. It
becomes the
below-ground root
system.
Epigeous vs. Hypogeous
Germination
First true
leaves
Epigeous
Germination
Hypogeous
Germination
Cotyledons
Food Storage Tissues
 Endosperm
in monocots.
 Cotyledons in dicots.
Coverings
 Seed
coat ( formed from integuments).
 In some cases the Pericarp (ovary wall).
Sunflower Seed
Germination Requirements of Seed
 Moisture
 Favorable
 Oxygen
temperatures
Light and Seed Germination
 May
be required for germination in some
species:


Small-seeded annual plants
Photo-dormant weed seeds
Seed Dormancy
A
seed is said to be dormant when it is
unable to germinate even though the
proper conditions for germination are all
present.
Viable vs. Non-viable Seed
 Viable:
the embryo is alive and capable of
germinating.
 Non-viable: the embryo is dead and
cannot germinate.
Viability Tests
#1 Place the seed in a bucket of water.
#2 Tetrazolium test.
#3 Cut test.
#4 Germination test.
Seeds Treated with Tetrazolium
Stages of Seed Germination
#1 Activation
#2 Nutrient digestion and translocation
#3 Seedling growth
Activation
of water – physical process
 Increased enzyme activity
 Cell elongation/enlargement
 Radicle emergence
 Imbibition
Radicle Emergence in Corn
Corn Seed
Radicle
Nutrient Digestion and
Translocation
 Stored
food converted from starches to
simpler forms (sugars).
 Sugars absorbed by cotyledons and
translocated to the embryo.
Seedling Growth
 Epicotyl
emergence.
 Continued development of the radicle.
Seed Provenance
 Refers
to the geographical region from
which the seed is collected.



Cold hardiness
Growth rate
Drought tolerance, etc…
 USDA
Forest Service “Super Trees”.
The End