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

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Vernalization is a physiological phenomenon that affects habitat and ecology of many grasses, not just the crops, so an understanding of the variability of its regulation will be important for understanding natural systems.
Effects of photoperiod and vernalization on the number of leaves at flowering in 32 Arabidopsis thaliana (Brassicaceae) ecotypes.
(2014), studying the same cultivar, observed phyllochron values of 93.3[degrees]C day [leaf.sup.-1], for vernalized seedlings, and 117.8[degrees]C day [leaf.sup.-1], for seedlings without vernalization.
They can bloom the first year, although in mild climates they may be treated as biennials, and some types need vernalization, an induced shortening of the vegetative period, to develop properly.
Some barley varieties require prolonged exposure to cold temperatures to initiate flowering, a process referred to as vernalization, whereas others initiate flowering without any obligation for vernalization.
All of what are commonly referred to as spring flowering bulbs also have a cold requirement called vernalization that, if not satisfied, prevents the bulbs from blooming.
Chief among these signals are light, temperature and vernalization, when flowering is promoted by prolonged exposure to cold temperatures.
Winter wheat is cold tolerant and must be subjected to a cold period during the winter (vernalization) to induce flowering in the spring.
They will germinate within a few days rather than requiring up to six weeks as they might without vernalization.