Non – germination of seeds due to absence of suitable conditions is termed as dormancy.
A physical or physiological condition of viable seed, which prevents germination even in the presence of favorable conditions
The seed dormancy is divided in to three groups
Cause of seed dormancy/ factor responsible for seed dormancy
Genetical factor / cause:
2. Embryo dormancy
3. Undeveloped cotyledon
4. Immature embryo
Coat imposed dormancy:
1. Seed coat factor:
a. Seed coat impermeable to water – i.e. water does not entered into seed coat
b. Seed coat impermeable to oxygen (0 is not entered in seed coat)
c. Mechanically resistant seed coat.
2. Embryo factor:
1. Dormant embryo
2. Immature/ Rudimentary embryo
3. Inhibitory factors:
Presence of germination Inhibitors in seeds i.e. presence of inhibitors or release of inhibitors.