ADAPTATION OF REGENERATED PLANTS OF Rubus arcticus L. TO ex vitro CONDITIONS USING HYDROPONICS

The results of studies on the adaptation of arctic bramble ( Rubus arcticus L.) plants of Astra and Sofia cultivars obtained by the clonal micropropagation method to non-sterile ex vitro conditions using the hydroponic method of cultivation are discussed in the article. The arctic bramble is a highly valuable species of forest berry plants in food and medicinal relations, rarely found and having a low yield in natural conditions. Adaptation to non-sterile ex vitro conditions is one of the limiting stages in clonal micropropagation. The survival rate of regenerated plants of arctic bramble of the studied cultivars in the conditions of a hydroponic system is 98 %, 1 month after planting in open ground - 69 %. Regenerated plants have stronger differences in morphometric parameters between clones within a cultivar than between cultivars. The arctic bramble planted in conglomerates formed shoots in the amount of 5.0 pcs. with an average length of 2.5 cm on the 20th day of adaptation. On the 45th day of arctic bramble plants after division into separate shoots had an average of 3.0 pcs. shoots with an average length of 8.3 cm. The arctic bramble plants of the Sofia cultivar have higher morphometric parameters of the above-ground and root systems compared to the Astra cultivar on the 45th day of cultivation in a hydroponic system: by the number of roots - by 30.3 %, by the total length of the roots - by 23 %, by the number of leaves - by 20 %, by the number of shoots - by 14 %, by the length of the shoots - by 10 %. The indicators of the development of the root system on a hydroponic installation depended on the varietal characteristics and the growing period. The arctic bramble plants have roots 10-20 cm long and shoot growths of 20-30 cm after 2 months of adaptation, which indicates its suitability for planting in open ground conditions.