Features of vegetative propagation of Thuja occidentalis L. ’Wagneri’

The features of vegetative propagation of Thuja occidentalis L. ’Wagneri’ using different types of stem cuttings depending on the effect of growth stimulants (aqueous solutions of Іndolylbutyric acid, Сharkor and Вiokor-char, as well as growth powders – Кornevin and Ukorzeniacz AB) were studied. The biological ability of the experimental stem cuttings to form adventitious roots was determined: rooting, degree of development of the root system (number of roots, their length, nature of their location on the cutting) and growth of the above-ground part of the rooted cuttings. Cuttings were carried out in the spring (second and third decades of April) with stem cuttings growing with a “heel” and semi-lignified cuttings. When grafting stem cuttings that grow with a “heel”, high rooting rates were obtained using the Ukorzeniacz AB growth powder and an aqueous solution of IMC, and semi-lignified cuttings were treated with growth powders (Ukorzeniacz AB and Kornevin). In these experimental variants, the formation of adventitious roots of three orders was observed on rooted cuttings, and the indicators of the total root length were maximum. The maximum growth rates of the above-ground part of rooted cuttings were observed with the use of growth powders (for cuttings growing with a “heel” when treated with Ukorzeniacz AB, for semi-lignified cuttings – with rooting powder). The study of the features of the morphogenesis of adventitious roots made it possible to trace the features of its stages and phases, determine their duration and characteristics, and also reveal the dependence of each of them on the type of cuttings and the influence of growth stimulants. The conducted studies have shown that it is possible to increase the rooting and number of adventitious roots and thus accelerate the regeneration process of different types of stem cuttings of T. occidentalis ’Wagneri’ if the studied types of cuttings and growth stimulants are used. This cultivar is best propagated by cuttings that grow with a “heel” and semi- lignified cuttings using growth powder (Ukorzeniacz AB). The proposed techniques will accelerate the rooting of stem cuttings of T. occidentalis ’Wagneri’ and obtain higher quality planting material.