Vernalization


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Vernalization

The induction in plants of the competence or ripeness to flower by the influence of cold, that is, temperatures below the optimal temperature for growth. Vernalization thus concerns the first of the three phases of flower formation in plants. In the second stage, for which a certain photoperiod frequently is required, flowers are initiated. In the third stage flowers are unfolded. See Flower, Photoperiodism, Plant growth

Vernalization

 

the reaction of a plant that is in the vegetative state to the effect of low, above-freezing temperatures (2°–10°C) for a certain period of time. Vernalization finds expression in the plant’s unique preparation to form the rudiments of flowers at the growing point. The German botanist J. G. Gassner was the first to study the phenomenon of vernalization (1918).

The phenomenon is characteristic of winter plants and some biennials and perennials. In some plants the formation of the flower rudiments may be an immediate result of vernalization. In many, for example, winter grasses, biennial henbane, and winter rape, flowering after vernalization will only occur during long days. Some plants show a capacity for vernalization at an early age. In winter grasses the reaction is observed during seed germination, and in biennial henbane it occurs after one month.

Vernalization is the result of the adaptation of plants to seasonal changes in climate. The physiological mechanisms of vernalization are probably associated with the formation of the plant hormones involved in inflorescence development.

The term “vernalization” is also used to designate an agricultural procedure by which the seeds of winter crops are exposed to a low, above-freezing temperature before planting so that the plants will blossom when planted in the spring. The technique is used in the selective breeding of plants.

V. Z. PODOLNYI

vernalization

[‚vərn·əl·ə′zā·shən]
(botany)
The induction in plants of the competence or ripeness to flower by the influence of cold, that is, at temperatures below the optimal temperature for growth.
References in periodicals archive ?
The simulation of the oat development cycle disregarded f(V), because in the ET-AN subphase there is no significant effect of vernalization on the tested genotypes.
Histone acetylation, VERNALIZATION INSENSITIVE 3, FLOWERING LOCUS C, and the vernalization response.
Vernalization is a response during the winter that is important for triggering flowering in the spring.
Vernalization is a term that describes the requirement of some plants for cold temperatures for floral development.
One of the FUL loci (called FUL1 by Preston & Kellogg, VRN1 by other authors) controls vernalization response in wheat, barley, and ryegrass (Lolium) (Yan et al.
Clones were planted in the field before winter to fulfill the vernalization requirement.
Biennial plants require a vernalization period in order to flower.
They need warm, moist soil to grow roots in August and September and up to 3 months of cold vernalization to flower the following year.
The researchers, who in 2003 cloned the first wheat vernalization gene, VRN1, discovered that VRN1 and VRN2 work together to confer the winter growth habit.
The glasswort (Salicornia ramosissima) occupies transition zones between temporarily flooded areas and those which are permanently flooded; those growing in the center of the population produce seeds that do not need light to germinate and are little affected by saline conditions, while those produced by plants on the periphery need light, require vernalization, and are sensitive to salinity.
The process, called vernalization, requires that the corm be exposed to temperatures of 2-5 [degrees] C (36-41 [degrees] F) for an extended period of time and then warmed up.
Vernalization in the cold for 23 months releases the gemmules from diapause and allows them to resume development when warmed to 20-23 [degrees] C.