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Vernalization (from Latin ''vernus'', "of the spring") is the acquisition of a plant's ability to flower in the spring by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower. Vernalization can also refer to herbal (non-woody) plants requiring a cold dormancy to produce new shoots and leaves. 〔K. Sokolski, A. Dovholuk, L. Dovholuk and P. Faletra Selbyana Vol. 18, No. 2, ORCHIDS (1997), pp. 172-182〕 Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process. This ensures that reproductive development and seed production occurs in spring and summer, rather than in autumn. The needed cold is often expressed in chill hours. Typical vernalization temperatures are between 0 and 5 degrees Celsius (40 and 50 degrees Fahrenheit). For many perennial plants, such as fruit tree species, a period of cold is needed first to induce dormancy and then later, after the requisite period of time, re-emerge from that dormancy prior to flowering. Many monocarpic winter annuals and biennials, including some ecotypes of ''Arabidopsis thaliana'' and winter cereals such as wheat, must go through a prolonged period of cold before flowering occurs. ==History of vernalization research== In the history of agriculture, farmers observed a traditional distinction between "winter cereals," whose seeds require chilling (to trigger their subsequent emergence and growth), and "spring cereals," whose seeds can be sown in spring, thence they germinate, and then flower soon thereafter. The word "vernalization" is a translation of "яровизация" ("jarovization") a word coined by Trofim Lysenko to describe a chilling process he used to make the seeds of winter cereals behave like spring cereals ("Jarovoe" in Russian).〔 Scientists had also discussed how some plants needed cold temperatures to flower, as early as the 18th century, with the German plant physiologist Gustav Gassner often mentioned for his 1918 paper.〔 Lysenco's 1928 paper on vernalization and plant physiology drew wide attention due to its practical consequences for Russian agriculture. Severe cold and lack of winter snow had destroyed many early winter wheat seedlings. By treating wheat seeds with moisture as well as cold, Lysenco induced them to bear a crop when planted in spring.〔 Later, however, Lysenco inaccurately asserted that the vernalized state could be inherited - i.e., that the offspring of a vernalized plant would behave as if they themselves had also been vernalized and would not require vernalization in order to flower quickly. Early research on vernalization focused on plant physiology; the increasing availability of molecular biology has made it possible to unravel its underlying mechanisms.〔 For example, a lengthening daylight period (longer days), ''as well as'' cold temperatures are required for winter wheat plants to go from the vegetative to the reproductive state; the three interacting genes are called ''VRN1'', ''VRN2'', and ''FT'' (''VRN3''). Due to plant flowering requiring the successful co-operation of several metabolic pathways, computer models that incorporate vernalization have also been made. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「vernalization」の詳細全文を読む スポンサード リンク
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