Clonal micropropagation of bakchar varieties of blue honeysuckle (Lonicera caeruleae L.)

The aim of the research is to study the effect of cytokinin growth regulators (zeatin, adenine, 2-isopentyl adenine, thidiazuron) on the multiplication coefficient at the proliferation stage; to study the effect of different concentrations of auxins (0.5, 1.0, 1.5 mg/l) indolebutyric acid (IBA) and indoleacetic acid (IAA) on rhizogenesis in vitro culture at the rooting stage. The objects of the research are micro-cuttings of blue honeysuckle of the Bakcharskaya selection varieties Vostorg, Ussulga, Strezhevchanka. The studies were conducted in 2024– 2025 in the biotechnology laboratory of the UdmFRC UB RAS according to the “Technology for obtaining planting material of fruit and berry crops improved from viruses, 2013” and in accordance with GOST R 59653–2021 “National standard of the Russian Federation. Planting material for fruit and berry crops. Technical conditions”. The multiplication coefficient of blue honeysuckle microcuttings on average by variety increased significantly to 6.5 pcs/explant using thidiazuron at a concentration of 0.1 mg/l, compared to 3.9 pcs/explant in the control variant and the least significant difference (95 % significance) equal to 1.2 pcs/explant. The use of zeatin and 2-isopentyl adenine at concentrations of 5.0 mg/l contributed to a slight increase in the multiplication coefficient of blue honeysuckle microcuttings to an average of 4.4 and 4.7 pcs/explant, respectively. The use of adenine at a concentration of 50 mg/l reliably reduced the multiplication coefficient of blue honeysuckle microcuttings to an average of 2.6 pcs/explant. Regardless of growth regulators, the micro cuttings of honeysuckle of the Strezhevchanka variety proliferated significantly more actively, where the reproduction coefficient averaged 6.1 pcs/explant. The use of IBA at concentrations of 1.0 mg/l and 1.5 mg/l significantly increased the rooting rate of blue honeysuckle microcuttings to an average of 67.7 and 74.2 %, respectively, with 54.8 % in the control variant and the least significant difference (95 % significance) equal to 7.5 %. The use of IAA at a concentration of 1.5 mg/l also led to a significant increase in the rooting of honeysuckle microcuttings, on average up to 62.3 %. More active root formation was observed in micro cuttings of honeysuckle of the Ussulga variety, regardless of the concentration of auxins, and amounted to an average of 67.2 %.