Microshoots formation of male cloudberry (Rubus chamaemorus L.) plants in vitro culture

The results of studies on clonal micropropagation of male plants of cloudberry (Rubus chamaemorus L.) of 4 forms selected in natural growth places in the Arkhangelsk and Vologda regions, the Republic of Karelia and the Khanty-Mansi Autonomous Okrug - Yugra. The fruits of R. chamaemorus have high nutritional and medicinal value. The experience of cultivating R. chamaemorus on depleted peatlands shows the prospects for creating berry plantations in such areas. It is necessary to improve the technology of clonal micropropagation of R. chamaemorus for Northern Russian origin forms. The maximum number (average 4.3-5.8 pcs.) and total length (9.0-17.6 cm) of R. chamaemorus microshoots in in vitro culture at the stage of shoot proliferation are noted when using the full composition of the MS nutrient medium, while similar indicators on the MS 1/2 and MS 1/4 media are 1.2-1.8 and 1.3-2.6 times lower, respectively. An increase in the concentration of 6-BAP cytokinin from 1.0 to 2.0 mg/l in the nutrient medium contributed to an increase in the number of microshoots of male R. chamaemorus plants in in vitro culture by 1.4-2.0 times and a decrease in its average length by 1.0 8-2.0 times, while no statistically significant differences in the total length of microshoots depending on the 6-BAP concentration are found in most forms. The biometric indicators of the Khanty-Mansiysk form in vitro are higher compared to the Arkhangelsk, Vologda and Karelian forms.