Germination
From Wikipedia, the free encyclopedia
- Not to be confused with Gemination, a concept in phonetics.
Germination is the process where growth emerges from a resting stage. The most common example of germination is the sprouting of a seedling from a seed of a flowering plant or gymnosperm. However, the growth of a hypha from a fungal spore is also germination. In a more general sense, germination can imply anything expanding into greater being from a small existence or germ.
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[edit] Seed germination
The seed of a higher plant is a small package produced in a flower or cone containing an embryo and stored food reserves. Under favorable conditions, the seed begins to germinate, and the embryonic tissues resume growth, developing towards a seedling. The part of the plant that emerges from the seed first is termed a radicle. In some definitions, the appearance of the radicle marks the end of germination and the beginning of "establishment", a period that ends when the seedling has exhausted the food reserves stored in the seed. These are critical phases in the life of a plant. The mortality between dispersal of seeds and completion of establishment can be so high, that many species survive only by producing huge numbers of seeds.
Some seeds require particular conditions to germinate, such as the heat of a fire (e.g., many Australian native plants), or soaking in a body of water for a long period of time.
[edit] Consumption of seedlings
Seedlings are commonly eaten as a health food. These seedlings are usually labeled sprouts, but in a botanical sense are actually seedlings. There is controversy in whether seedlings, or sprouts, are really worth eating. These seedlings are many times used as organic foods eaten for their concentrations of certain vitamins the seedling naturally contains. This can be viewed out of proportion as the seedling is usually too small to contain enough vitamins or minerals to be in line with the amount they are claimed to obtain.
[edit] Stratification of seeds
Seeds must be mature and environmental factors must be favorable before germination can take place. When a mature seed is placed under favorable conditions and fails to germinate, it is said to be dormant. The length of time plant seeds remain dormant can be reduced or eliminated by a simple seed treatment called stratification. Seeds should be planted promptly after stratification.
[edit] Requirements for germination
Every variety of seed requires a different set of variables for successful germination. Typically these involve the proper levels of water, oxygen, temperature, light, and soil conditions. Most seeds respond the best when water levels are enough to moisten the seeds but not soak them, when temperatures are slightly higher than room-temperature, and when oxygen is readily available. However, as stated earlier, this depends greatly on the individual seed variety. For example, some seeds will only germinate when temperatures reach in the hundreds of degrees (after a forest fire).
[edit] External links
- The Seed Site: collecting, storing, sowing, germinating, and exchanging seeds, with pictures of seeds, seedpods and seedlings.
- Sowing Seeds A survey of seed sowing techniques.
- Seed Germination: Theory and Practice, Norman C. Deno, 139 Lenor Dr., State College PA 16801, USA. An extensive study of the germination rates of a huge variety of seeds under different experimental conditions, including temperature variation and chemical environment. germination is fun
- How to Germinate Seed A bonsai propagator's views.
