Seed Dormancy
Definition:
Non – germination of seeds due to absence of suitable conditions is termed as dormancy.
OR
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
1. Endogenous
2. Exogenous
3. Combined
Cause of seed dormancy/ factor responsible for seed dormancy
Genetical factor / cause:
1. Physiological
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.