germination

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germination,

in a seed, process by which the plant embryo within the seedseed,
fertilized and ripened ovule, consisting of the plant embryo, varying amounts of stored food material, and a protective outer seed coat. Seeds are frequently confused with the fruit enclosing them in flowering plants, especially in grains and nuts.
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 resumes growth after a period of dormancy and the seedling emerges. The length of dormancy varies; the seed of some plants (e.g., most grasses and many tropical plants) can sprout almost immediately, but many seeds require a resting stage before they are able to germinate. The viability of seeds (their capacity to sprout) ranges from a few weeks (orchids) to up to 1,200 years (sacred lotus) and 2,000 years (date palm). The percentage of viable seed decreases with age. Dormancy serves to enable the seed to survive poor growing conditions; a certain amount of embryonic development may also take place. Dormancy can be prolonged by extremely tough seed coats that exclude the water necessary for germination. Internally, growth is regulated by hormones called auxins. When the temperature is suitable and there is an adequate supply of moisture, oxygen, and light—although some seeds require darkness and others are unaffected by either—the seed absorbs water and swells, rupturing the seed coat. The growing tip (radicle) of the rudimentary root (hypocotyl) emerges first and then the growing tip (plumule) of the rudimentary shoot (epicotyl). Food stored in the endosperm or in the cotyledons provides energy for the early stages of this process, until the seedling is able to manufacture its own food via photosynthesisphotosynthesis
, process in which green plants, algae, and cyanobacteria utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the presence of chlorophyll. Some of the plants that lack chlorophyll, e.g.
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.

Germination

 

the ability of a seed to yield normal sprouts after a set period of time in defined sprouting conditions. In the USSR seed germination is defined by state seed inspection in controlled seed analysis following a method prescribed by the All-Union State Standard (GOST 12038-66). The number of normally sprouted seeds is expressed as a percentage of the total number of seeds taken for analysis. In defining the usefulness of seeds for planting, germination is one of the most important qualities. This is of great productive importance. Seeds with high germination rapidly and conceitedly yield shoots, guaranteeing large harvests under proper conditions. High seed standards are required for norms of germination, so that first-class seeds of the basic grain crops except for hard wheat must have a germination not lower than 95 percent, and hard wheat must have one not lower than 90 percent. Seeds that do not meet the standard may not be used for planting. Germination depends to a great extent on the techniques of cultivation, method of harvesting, and storing conditions.

M. K. FIRSOVA

germination

[‚jer·mə′nā·shən]
(botany)
The beginning or the process of development of a spore or seed.
(petrology)
References in periodicals archive ?
In autumn sowing period optimal laser treatment (D3) had impact on decrease of the occurrence of hard seeds from 9% to 6% and increase of the germination rate from 74% to 79%, growth of shoot for 0.
3% with the seed germination rate of 17% under the condition of constant temperature, suggesting the seeds in dormant state.
For 25[degrees]C, higher seed germination is observed until 6 days of storage, for seeds stored inside the fruit (Table 4), where can be observed better germination rates at 25 and 30[degrees]C, and the seeds can be stored up tol 6 days.
We do not know if certain mycorrhizal fungi occurred on a specific host tree could bring about a higher germination rate of D.
Concerning PVH batch, a decrease in germination percentage and germination rate was observed when sowed in December (five months after the first trial), whose average temperatures were higher as compared to previous assays.
TABLE 2 Results of two-way ANOVA show the impact of seed colour and temperature of incubation on germination rate index of (a) L.
These findings allow us to easily support the use of older seeds for sowing, despite a decrease in germination rate this will decrease pest populations and thus reduce the infestation of future crops.
rosea: The main effect of light quality was recorded on germination rate.
The low GSI found in seeds subjected to mechanical scarification is due to an insufficient water absorption caused by a small rupture, thus affecting the germination rate.
Thus, to overcome this type of dormancy, mechanisms of tegument scarification that increase germination rate and can also speed up the germination process have been developed (NUNES et al.
Five out of 10 would show a 50 percent germination rate, and eight out of 10 equals 80 percent germination.