THE DYNAMICS OF THE DEVELOPMENT OF THE SHRUB WILLOWS (SALIX, SALICACEAE)

The article presents the results of observations of the seasonal dynamics of the growth of annual shoots of two species of shrub willows: Salix triandra and Salix viminalis. Object: genetically aligned model inbred-clonal populations of S. triandra and S. viminalis. Material: growing shoots on annual cuttings. Methods: comparative morphogenetic, chronobiological, numerical analysis of the series of dynamics. Results. Clones of two species of shrub willows, phylogenetically distant from each other, demonstrated high productivity along the length of shoots on annual cuttings. On the shoots of the strongest clone of S. triandra, the length of mature shoots was 176–215 cm, on the shoots of the strongest clone of S. viminalis - 132–192 cm. As the shoots grow, the differences in length between them increase. No significant influence of the clone factor on the dynamics of the daily growth of S. triandra shoots was revealed, and the effect of the clone factor on the dynamics of the daily growth of S. viminalis shoots is insignificant. In the seasonal dynamics of the daily growth of shoots, regardless of their species and clonal affiliation, three stages of shoot development were identified: spring, early summer, and late summer. The transitions between stages are synchronized in clones regardless of species. Qualitative interspecific and interclonal differences in the seasonal dynamics of daily shoot growth were not revealed. Quantitative interspecific differences in the seasonal dynamics of daily increment were revealed only at the second stage of shoot development, with high values of daily increment. Significant interclonal differences in the seasonal dynamics of daily growth were not found: differences between the trajectories of shoot development are due to intraclonal variability within each species. Recommendations. When planning, creating and operating pure and mixed cultures of S. triandra and S. viminalis, take into account the fundamental similarity in the seasonal dynamics of the development of shoots of different species of shrub willows. When harvesting and planting cuttings, use a homogeneous mother material. Culling of weak cuttings that are lagging behind in development should be carried out in the first year of life.