II. 30 Vernalization requirements of winter barley varieties.
W. Schmuetz, Landessaatzuchtanstalt, Universität Hohenheim, D-7000 Stuttgart 70, FRG. "R".
In barley breeding knowledge of vernalization requirements is important for several reasons. Using material with low vernalization requirements, such data may help saving considerable time during the necessary presowing vernalization treatment of parents for crosses, as well as during the advancement of early generations. Furthermore vernalization requirements are correlated with winter hardiness (1), and can given some additional information on the expression of that complex factor.
According to a method described earlier (2, 3), the vernalization requirements were determined for 59 winter barley varieties (Table 1) during the years 1974 to 1977. Seeds of every variety under investigation were germinated and then exposed to 1 C at darkness for 75, 60, 45, 30, 15 and 0 days. Immediately after this treatment of graduated duration all seeds were planted at the same day in a greenhouse. The growing temperature ranged from 18 to 23°C; a 16-hours day was applied. Neither additional vernalization, nor devernalization did occur to a measurable extent during growth.
The precise classification of any variety investigated was possible by recording that number of days of presowing vernalization treatment necessary for undelayed heading and ripening. This is cited as vernalization requirement.
Figure 1 shows a winter barley variety with a vernalization requirement of 30 days. All plants with 75, 60, 45, and 30 days of presowing vernalization treatment (four rows from right to left) headed without remarkable delay; the plants with 15 to 0 days presowing vernalization (two rows at left) remained in the vegetative growth stage.
Figure 1. Vernalization requirements of winter barley varieties (W. Schmuetz).
The data given in Table 1 indicate, that the vernalization requiremenets of the winter barley varieties investigated range from 0-15 days to 45-60 days, with an average of 32 days. These results confirm, that out of all winter cereals grown in Central Europe (winter wheat, winter rye, winter barley), barley has the lowest average in vernalization requirements, but still shows large varietal differences up to 45 days. The findings are published in order to provide barley research with the necessary information.
Further development-physiological factors, like the day length requirements of all winter barley varieties mentioned in Table 1, and the influence of vernalization requirements as well as of day length requirements on winter hardiness, are currently under study.
References:
1) Schmuetz, W. 1977. Neuere Ergebnisse zur Beziehung zwischen Vernalisationsbedarf und Winterfestigkei bei Getreide. Bericht uber die Arbeitstagung 1976 der Arbeitsgemeinschaft der Saatzuchtleiter, Bumpenstein, dsterreich, 23.-25. Nov. 1976, p. 77-86.
2) Schmuetz, W. 1963. Untersuchungen und Methoden zur Bestimmung einzelner Komponenten der Winterfestigkeit bei Weizen. Z.F. Ackeru. Pflanzenbau 118:125-148.
3) Schmuetz, W. 1976. Vernalisationbedarf bei Wintergetreide. I. Untersuchungen zur Methodik der Bestimmung. SAFA-Saatgutwirtschaft 28:299-302, 344-345.
