Why Is Seed Dormancy Important to Conservation?.

Seed dormancy is important to conservation because plants of many wild species are needed for restoration projects, and failure of germination due to seed dormancy can be a major impediment in producing these plants. Further, some species are endangered or threatened, and propagation from seeds may be critical for their survival. Thus, there are many reasons for germinating dormant seeds of wild species for conservation. However, sowing seeds in the field often results in little, or no, germination, unless nondormant seeds are sown when environmental conditions are favorable for germination. Information on the kind of dormancy in seeds facilitates determining how dormancy can be broken. There are five major kinds (classes) of seed dormancy, and these will be described briefly. Physiological dormancy (PD) is the most common class of seed dormancy and is broken in nature when conditions are not favorable for seedling establishment. To break PD, information is needed about the conditions in the habitat between the time of seed maturation/dispersal and germination. An example will be given of the breaking of PD via (1) a single relatively short treatment, e.g. hot (dry) summer; (2) a sequence of different conditions, e.g. summer→ autumn→ winter in the temperate zone; and (3) prolonged (2-3 years) incubation at warm, wet habitat conditions. One example will be presented to illustrate how difficult it may be to germinate seeds after dormancy has been broken. Physical dormancy (PY) is the second most common class of dormancy and is broken when the environment is favorable for seedling establishment. Breaking PY involves two steps: one set of conditions makes seeds sensitive to dormancy-break and a second set causes the water gap on the seed to open. In conclusion, information about the life cycle and habitat of a species will help us develop effective seed dormancy-breaking strategies.