REGENERATION FEATURES OF SOME LILAC CULTIVARS IN VITRO

The aim was to optimize cultivation techniques at the micropropagation stage of Syringa L. cultivars. The studies were conducted in the Plant Biotechnology Laboratory of the Volgograd Regional Botanical Garden (VRBG) in 2022–2023. The following genotypes were selected as objects, represented in the collection by single specimens: ‘Marshal Zhukov’, ‘Marshal Malinovsky’, ‘Mikhail Sholokhov’, ‘Konstantin Zaslonov’, ‘Malenky Prince’ and ‘Mikhailo Lomonosov’. The optimal sterilization mode was 5 % lysoformin, while the exposure time was 3 minutes. With this mode, the yield of sterile lilac explants was maximum – 90 %. The study showed the influence of genetic characteristics and the composition of the nutrient medium on the regeneration potential of Syringa L. It was found that on the WPM (Wood Plant Medium, 1981) nutrient medium added by 1.0 mg/l 6-BAP (6-benzylaminopurine), the regenerated Syringa L. plants were characterized by active growth of microshoots and the greatest height. In the ‘Mikhail Sholokhov’ cultivar, it was 47.4 ±3.7 cm, in ‘Konstantin Zaslonov’ cultivar – 42.7 ±4.1 cm, in ‘Mikhailo Lomonosov’ – 31.2 ±3.2 cm, in ‘Marshal Malinovsky’ – 30.3 ±2.5 cm, in ‘Malenky Prince’ – 30.1 ±3.2 cm, in ‘Marshal Zhukov – 23.7 ±3.2. The maximum multiplication coefficient was recorded for the cultivar ‘Mikhail Sholokhov’ (7.8 ±3.1), the minimum – for the cultivar ‘Marshal Zhukov’ (3.7 ±1.9). When studying the effect of growth regulators and their concentrations during cultivation on the WPM medium, it was shown that 6-BAP at a concentration of 1.0 mg/l was more effective than 2-iP (2-isopentyl adenine) of the same concentration. At the rooting stage, the optimal solution is to use the WPM nutrient medium supplemented with indolebutyric acid (IBA) at a concentration of 1.0 mg/l. According to such an indicator as root length and number of roots, the optimal solution is to use IBA at a concentration of 1.0 mg/l compared to IAA. In this case, the number of rooted plants was 100 %.