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Background. Woolly-twigged willow – Salix gmelinii – a highly productive type of willow that is used to create raw material plantations. The high productivity of this species is due to the ability to form powerful annual shoots. Purpose of research: structural analysis of seasonal growth of S. gmelinii shoots in culture. Materials and methods. Object: model inbred-clone population. Material: increasing annual shoots. To obtain and process the initial data, a set of methods of experimental botany, chronobiology, and analysis of time series was used. Results. Under the conditions of this experiment, the length of annual shoots varied widely: from 34 to 252 cm. The discreteness of the distribution of shoots by their annual increment is revealed. The established discreteness of the development of shoots is due to different terms for the completion of growth. The discreteness of the growth completion dates is associated with the cyclic alternation of peaks and dips in the daily increment of shoots. The cyclicity of the daily increase is determined by infradian rhythms with a period of 14, 18 and 27 days, as well as subannual rhythms with a period of 54 days. Six types of shoot development were identified, which differ in the duration of growth. Conclusions. The discreteness of the development of shoots is determined by the cyclical seasonal dynamics of daily increment. The cyclical nature of the seasonal dynamics of the daily increment of shoots is determined by the interaction of biorhythms with different periods of fluctuations. In most cases, differences in the seasonal dynamics of shoot growth are due to intra-clonal variability. Some clones are characterized by high annual growth of shoots, regardless of other factors. To ensure high annual growth rates of shoots, it is necessary to create favorable conditions for their development in the first half of the vegetation period. The obtained results are recommended to be used in the selection of S. gmelinii for high and stable productivity, as well as in the planning, creation and operation of crops. |
