What are the basic factors in seed germination?

Answer 1

The three factors necessary for germination of a seed are:

(1).Water:

Seed obtains water from its environment, i.e from the soil, in natural conditions. The water is absorbed all over the surface but mainly through the micropyle. Two main uses of water are:

(i) The seed swells and consequently the seed coat ruptures allowing the elongating the radicle to come out and form the root system.

(ii). water is necessary for chemical reaction and for the enzymes to act on the food stored in the cotyledons or the endosperm so that it is converted into diffusable form dissolved and utilized by the growing embroyo.

(2).Suitable temperature:

Both very low and high temperatures are unsuitable for germination.A very low temperature inhibits the growth of the embroyo and a very high temperature destroys its tissues.A moderately warm temperature(25 degrees to 35 degrees centigrade) is usually favourable for germination and it is also called optimium temperature.Seeds of tropical plants need a higher temperature than those of the temperate regions.

(3).Oxygen:

During germination there is rapid cell division and cell growth for which energy is required.This energy is available only by respiration(for oxidation of food) and hence the need for oxygen(or air).

Answer 2

Following factors are to be taken in to consideration foe seed germination-:

1) Dormancy period -- A seed requires to undergo a period of dormancy after its formation. During this period the seed 'rests' and may refuse to germinate properly. This period varies from seed to seed . Seeds of water melon or red gourd do not have a dormany period and may germinate easily immediately after their formation in the fruit. Others require dormancy period ranging from a few weeks to a few months.

2) Viability of a seed -- It is exactly like expiry date/period of a commercial product. It must not be confused with the dormancy or 'resting period'

After the resting period a seed bcomes ready to germinate.But this readiness is not for ever. It literally expires after cerain period.After that seed will not germinate. This 'ready to germinate' period is the viability period of a seed. It may vary from a few years to many centuries.Seeds of Lotus are reported to have germinated even after eight hundred years! In that case their viability period is atleast that much if not more.

After considering the two inherent factors, let us now look in to the external factors.

3) Soil moisture or water -- This is required to trigger the mechanism of germination.In in absence of moisture the seeds can not germinate ; but when it is available it is imbibed by the seed coat and the enzymes in side become active and functional. The amount of water does not matter in the initial stages; But later on it becomes critical.

4) Soil Texture - Does not matter during germination. Seeds can even germinate with out soil on the piece of a moist blotting paper.

5)Soil pH--Should too acidic. pH 5 to 8 is alright.

6) Soil temparature - It should be on the warmer side.Lesser the temp. lesser the rate of germination.

7) Light - It does not affect the process of germination; but some seeds do germinate better in the ABSENCE of light. They like darkness for germination it seems.

Answer 3

Factors affecting seed germination

Seed germination depends on both internal and external conditions. The most important external factors includetemperature, water, oxygenand sometimes light or darkness.[2] Various plants require different variables for successful seed germination, often this depends on the individual seed variety and is closely linked to the ecological conditions of a plant'snatural habitat. For some seeds, their future germination response is affected by environmental conditions during seed formation; most often these responses are types of seed dormancy.

• Water - is required for germination. Mature seeds are often extremely dry and need to take in significant amounts of water, relative to the dry weight of the seed, before cellularmetabolism and growth can resume. Most seeds need enough water to moisten the seeds but not enough to soak them. The uptake of water by seeds is called imbibition, which leads to the swelling and the breaking of the seed coat. When seeds are formed, most plants store a food reserve with the seed, such asstarch, proteins, or oils. This food reserve provides nourishment to the growing embryo. When the seed imbibes water, hydrolytic enzymes are activated which break down these stored food resources into metabolically useful chemicals.[2] After the seedling emerges from the seed coat and starts growing roots and leaves, the seedling's food reserves are typically exhausted; at this point photosynthesis provides the energy needed for continued growth and the seedling now requires a continuous supply of water, nutrients, and light.

• Oxygen - is required by the germinating seed formetabolism.[3] Oxygen is used in aerobic respiration, the main source of the seedling's energy until it grows leaves.[2] Oxygen is an atmospheric gas that is found in soil pore spaces; if a seed is buried too deeply within the soil or the soil is waterlogged, the seed can be oxygen starved. Some seeds have impermeable seed coats that prevent oxygen from entering the seed, causing a type of physical dormancy which is broken when the seed coat is worn away enough to allow gas exchange and water uptake from the environment.

• Temperature - affects cellular metabolic and growth rates. Seeds from different species and even seeds from the same plant germinate over a wide range of temperatures. Seeds often have a temperature range within which they will germinate, and they will not do so above or below this range. Many seeds germinate at temperatures slightly above room-temperature 60-75 F (16-24 C), while others germinate just above freezing and others germinate only in response to alternations in temperature between warm and cool. Some seeds germinate when the soil is cool 28-40 F (-2 - 4 C), and some when the soil is warm 76-90 F (24-32 C). Some seeds require exposure to cold temperatures (vernalization) to break dormancy. Seeds in a dormant state will not germinate even if conditions are favorable. Seeds that are dependent on temperature to end dormancy have a type of physiological dormancy. For example, seeds requiring the cold of winter are inhibited from germinating until they take in water in the fall and experience cooler temperatures. Four degrees Celsius is cool enough to end dormancy for most cool dormant seeds, but some groups, especially within the family Ranunculaceae and others, need conditions cooler than -5 C. Some seeds will only germinate after hot temperatures during a forest fire which cracks their seed coats; this is a type of physical dormancy.

Most common annual vegetables have optimal germination temperatures between 75-90 F (24-32 C), though many species (e.g. radishes or spinach) can germinate at significantly lower temperatures, as low as 40 F (4 C), thus allowing them to be grown from seed in cooler climates. Suboptimal temperatures lead to lower success rates and longer germination periods.

• Light or darkness - can be an environmental trigger for germination and is a type of physiological dormancy. Most seeds are not affected by light or darkness, but many seeds, including species found in forest settings, will not germinate until an opening in the canopy allows sufficient light for growth of the seedling.[2]

Scarification mimics natural processes that weaken the seed coat before germination. In nature, 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. Others need to be passed through an animal'sdigestive tract to weaken the seed coat enough to allow the seedling to emerge

Answer 4

The basic factors in seed germination include water, oxygen, temperature, and light. Water helps to soften the seed coat and initiate metabolic processes, oxygen is required for respiration, temperature affects enzymatic activity, and light can trigger germination in some plant species. These factors work together to signal to the seed that it is time to begin growing into a new plant.

Answer 5

humidity, temp, light, seed age... and many more

the main three are oxygen, water, temperature.

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Answer 6

The factors that affect seed germination is moisture and warmth levels. To maintain the proper germination conditions, use germinating supplies.

Answer 7

What are the basic factors in seed germination

Answer 8

1. An adequate supply of moisture

2. An adequate supply of oxygen

3. A favorable temperature

4. Proper soil conditions

5. Sufficient sunlight

Answer 9

Heat and moisture. If only one moisture.