Latency and germination of seeds. Pregerminative treatments.
The seeds of most plants do not germinate immediately after ripening. At maturity they enter a state of latency of varying duration depending on the species, latency that can last from a few weeks or months to several years. The seeds of some species germinate after a dry storage interval or in the following spring. The seeds of other species germinate irregularly over a period of 2 to many years.
When we multiply plants by seeds, it is advisable to shorten this latency time that is mainly due to two causes: the impermeability of the seed cover and the internal latency of the embryo itself. In some species there is only one cause, but in many species both occur. To overcome lethargy, procedures such as immersion in sulfuric acid, immersion in hot water close to boiling, immersion in cold water, etc. are resorted to. Treatments to overcome this lethargy vary by species and type of latency.
The state of dormición, latency or lethargy it is defined as the inability of an intact and viable seed to germinate under conditions of temperature, humidity and concentration of gases that would be suitable for germination. In particular, in the forestry sector the word latencia, which comes from the Latin "latensis" and means hidden, hidden or apparently inactive to refer to this inability of the seed to germinate, which can be a problem for example for seedling production programs in nursery. The latency is established during the formation of the seed, and has an important function that is to restrict germination in the mother plant before its dispersion in the field. In addition, it is considered that latency is an adaptation that contributes to the survival of the individual, since it restricts germination when environmental factors are unfavorable for the development of the seedling.
This booklet is an attempt to provide information on the different types of dormancy in seeds of forest species as well as on the different techniques / pregerminative treatments to accelerate the germination process.