Seed Dormancy and Survival Mechanisms

What is the purpose of soaking seeds in hot water followed by cold water for 24 hours?

Which chemical is used for soaking seeds to modify a hard or impermeable seed covering?

What is cold stratification primarily used for?

What type of environment is required during cold stratification?

How long can post-harvest dormancy last in freshly harvested seeds stored under dry conditions?

Which treatment has been found to stimulate germination in many citrus species?

What should be done to seeds after acid treatment to ensure safety?

What is the main role of endogenous growth promoting substances during cold stratification?

What does dormancy in seeds primarily help to conserve?

Which type of dormancy is characterized by hard seed coats that prevent germination?

Which method involves breaking or scratching the seed coats to aid germination?

What is a factor that does NOT contribute to seed dormancy?

Which type of dormancy requires several weeks to months after harvest for the embryo to mature?

How can chemical inhibitors in seeds be reduced to allow for germination?

Which of the following is NOT a method to overcome seed dormancy?

What is double dormancy in seeds?

Dormancy is a state of suspended growth and development in organisms. It helps conserve energy.
Dormancy is a natural survival mechanism, not a failure.

Seed coat dormancy: The seed coat is hard and impermeable, preventing germination. Examples: Malvaceae, Pits of stone fruits, shells of nuts
Dormancy due to rudimentary embryos: The embryo is not fully developed at the time of seed dispersal. It requires time to mature before it can germinate. Examples: Pinus species, palms
Dormancy due to chemical inhibitors: Seeds contain chemicals that inhibit germination. These inhibitors can be leached out with water or adsorbed by water.
Dormancy due to internal factors: The embryo is physiologically dormant and requires specific conditions, such as moist chilling treatments, to resume growth. Examples: Freshly harvested seeds of apple, grapes, peach, and apricot
Double dormancy: Seeds exhibit both seed coat dormancy and embryo dormancy. Example: Cercis occidentals

Mechanical scarification: Physically breaking or scratching the seed coat to make it permeable.
Soaking in water: Softening the seed coat and washing away inhibitors.
Acid treatment: Modifying the seed coat using concentrated hydrochloric acid or sulfuric acid for a brief period.
Cold stratification: Exposing seeds to moisture, oxygen, and cool temperatures to promote physiological changes in the embryo. This process involves placing seeds in a moist medium like sand, peat, or vermiculite and storing them at slightly above freezing temperatures for an extended period, usually one to four months.
Dry storage: Promoting after-ripening in dormant seeds.
Treatment with chemicals: Soaking seeds in solutions of potassium nitrate, gibberellic acid, or thiourea to stimulate germination.