Vernalization: Cold Treatments and Flowering • 55 



tive significance of such behavior in regions with a period of winter 

 cold, itself unfavorable to growth, need not be belabored. 



The cold treatment of germinating seeds in order to hasten 

 subsequent flowering has come to be known as vernalization. This 

 is a translation of the Russian yarovizatsya, and both words com- 

 bine the term for "spring" (Russian, yarov; Latin, ver) with a 

 suffix implying "to make" or "become," reflecting the ability of 

 such cold treatments to convert "winter" strains of cereals to the 

 "spring" habit by satisfying their cold requirement. Winter cereals 

 must normally be planted in late fall or winter in order to flower 

 and produce a crop in the subsequent year, whereas spring varieties 

 may be planted in the spring of the year in which the crop is 

 expected. The terms vernalization or yarovizatsya both actually 

 postdate the first observations of such effects by many years, but it 

 was Russian attention to the possible practical values of the process, 

 particularly in the 1930's, that brought it generally to world-wide 

 notice. For the history of early work on vernalization, see McKinney 

 (1940) and Whyte (1948). 



Vernalization is probably the only aspect of plant physiology 

 that ever became involved in political ideology. The agronomic 

 use of vernalization in the Soviet Union was popularized by T. D. 

 Lysenko, who viewed the effect as an actual inheritable conversion 

 from winter to spring habit; later he even claimed the conversion of 

 one species of wheat into another. Lysenko's theory eventually led 

 to the establishment of a Marxist form of Lamarckism-an old 

 and thoroughly discredited view, which holds that changes pro- 

 duced by the environment are directly inherited by the offspring of 

 the changed organism— as the Soviet dogma in biology. The adopt- 

 ing of this view by the Soviets was probably partly due to simple 

 opportunism on Lysenko's part, as he was its chief interpreter. Some 

 of the finest biologists in the U.S.S.R. refused to support the official 

 line and, as a result, simply disappeared or were demoted. This 

 unfortunate episode in the history., of science has been recounted 

 and analyzed by Huxley (1949) and Zirkle (1949) but does not 

 appear to have run its course even yet, so that Soviet biology 

 still labors under a disadvantage. Ironically, vernalization has not 

 proved to be of great agronomic importance, since the breeding 

 of varieties suitable for particular climates and uses has been far 

 more successful. At present, the chief practical applications of an 



