Vernalization
It is a process that initiates flowering in plants by exposing them to prolonged cold temperature. Vernalisation, along with additional seasonal cues, induces the plant’s flowering process. Many temperate plants require a vernalisation process to accelerate their flowering. Typical vernalisation temperature ranges somewhere between 1 and 7°C. The prolonged low temperature will reduce the vegetative phase, and eventually induce the flowering phase.
Extended Reading: Photoperiodism and Vernalisation
Stratification
It is a process of seed stimulation to promote germination. Most seeds experience dormancy during their embryonic phase. This dormancy must be broken by the stratification process to ensure germination. Under natural conditions, the seed spends considerable time in the ground during winter to stimulate its seed coat. The seed coat is softened by weathering actions and frost. Artificially, the seeds can be cold treated in temperatures between 1° and 3°C. Some seeds need a warm stratification at first, which is then followed by cold stratification. The ideal temperature for warm stratification is between 15° and 20°C.
Also Read: Seed Dormancy
Difference between Vernalization and Stratification
|
Vernalization |
Stratification |
|---|---|
|
It is a technique that promotes a plant’s flowering process. |
It is a technique that breaks seed dormancy and promotes the germination process. |
|
It is a cold treatment process. |
It involves both warm and cold treatment. |
|
The ideal temperature for vernalisation ranges somewhere between 1°and 7°C. |
The temperature for warm treatment is between 15° and 20°C. This is usually followed by cold treatment that ranges between 1° and 3°C. |
|
Here, the low temperature reduces the vegetative phase and eventually induces the flowering phase. |
Here, the hard and impermeable seed coat is softened by frost. |
Frequently Asked Questions on Difference between Vernalization and Stratification
What is seed dormancy?
Some seeds fail to germinate even under favourable external conditions. Such seeds undergo a period of dormancy under endogenous conditions. Thus, they create hard and impermeable seed coats to avoid germination. This seed dormancy can be broken by mechanical abrasions, chemical treatments, cold treatments, etc.
What is devernalisation?
The reversal of vernalisation is termed devernalisation. The vernalised plants are exposed to subsequent low and high temperatures to devernalise. Usually, onions are subject to devernalisation, in order to produce enlarged bulbs instead of making flowers.
What is scarification?
Scarification involves altering or weakening the seed coat to encourage germination. This technique is used to break physical dormancy, while stratification breaks physiological dormancy. Also, scarification involves removing or scratching seed coats instead of cold treatment.
Visit BYJU’S Biology for more exciting topics.
Comments