Seed germination is initiated by water absorption and warmth, breaking dormancy through mechanisms like seed coats, inhibitors, scarification, light, or stratification. Dormancy is caused by thick seed coats, inhibitors like abscisic acid or phenolics, and insufficient development, and can be overcome by scarification, repeated rain, stratification, or fungus association in some seeds like lettuce or orchids.

1. Seed Germination:Emergence of Radicle through Seed Coat
Water Warm Temperature
So if you want to store seeds what are the conditions? Dry Cold
Dormant seeds need more than moisture and warmth:
Thick Seed Coat
Thin Seed Coat
Insufficient Development
Inhibitor: Abscisic Acid
Inhibitor: Phenolics
Scarification
Light
Soil Fungus Association
Stratification > Vernalization
Leaching by Repeated Rain
Kentucky Coffee Tree
Lettuce
Orchids
Most CT feral plants
Cacti
Darkor or Pea
Dormancy is caused by: Is overcome by: Example:
Seeds lacking dormancy need:
nick digest
scrub fire
freeze-thaw cycles
6 weeks at 4° C 20° C

2. Barley Seed Germination
Fruit+Seed Coat
Endosperm
Aleurone Layer
Storage Protein
Amino Acids
hydrolysis
translation
transcription
hydrolysis
starch
sugar
α-amylase
RNA
DNA
GA
imbibition
water
radicle apex
shoot apex
growthcotyledon
monocot
maltose
Embryo
exocytosis

3. Capsella Seed:
Seed Coat
Endosperm
Embryo
Shoot Apex
Cotyledons - dicot
Hypocotyl
Radicle
Root Apex
Micropyle

4. Lettuce Seed Germination
660 nm
730 nm
dark
Seed Coat
translation
transcription
hydrolysis
starch
sugar
α-amylase
RNA
DNA
imbibition
water
radicle apex
shoot apex
growthdicot
photoreversibility
Pfr Pr
photoactivation
Embryo
phytochrome
red and
white light
stimulate
germination
cotyledons