Seed dormancy

Seed dormancy is a state in which a viable seed delays germination until conditions favor growth. It helps plants time germination to improve seedling survival.

Abscisic acid: A plant hormone that promotes seed maturation and dormancy and inhibits germination. High levels help maintain dormancy and suppress the growth processes that initiate germination.
Seed viability: A seed's capacity to remain alive and germinate under suitable conditions. A dormant seed is viable; a dead seed cannot germinate even after dormancy is relieved.
Seed stratification: A treatment that exposes seeds to moist conditions at suitable temperatures to release dormancy. Cold or warm stratification reproduces seasonal cues required by many dormant seeds.
Physical dormancy: Dormancy caused by a water-impermeable seed or fruit coat. It is released when the coat is disrupted by environmental or treatment processes.
Vivipary: The germination of a seed while it is still attached to the parent plant. Vivipary is the opposite timing strategy: germination begins before seed dispersal.
Gibberellin: A plant hormone that promotes growth, including the germination of many seeds. Gibberellin often counteracts abscisic acid by stimulating embryo growth and reserve mobilization.
Quiescence: A reversible pause in growth caused directly by unfavorable external conditions. Unlike dormancy, quiescence ends when the immediate external constraint is removed.
Scarification: The weakening or removal of a seed coat to improve water uptake or permit embryo emergence. Mechanical or chemical scarification releases dormancy caused by a resistant seed coat.
Physiological dormancy: Dormancy caused by physiological conditions within the embryo that prevent germination. It commonly requires temperature, light, or chemical signals to be relieved.
Seed dispersal: The movement of seeds away from their parent plant by animals, wind, water, or other means. Dormancy often delays germination after dispersal, separating seed arrival from establishment.

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