PRESERVATION OF BIODIVERSITY OF THE GENUS SYRINGA L. IN THE IN VITRO COLLECTION OF MBG RAS

Syringa L. is a genus of woody plant species cultivated in temperate climate regions mainly for ornamental spring flowering. In Russia and abroad, the breeding work is focused on several areas, including original flowering, winter hardiness, disease resistance, etc. Conservation of plant genetic diversity, including ornamental crops, for current and future breeding programs is the main task of botanical gardens and other research centers. The biotechnological method is considered one of the most effective and reproducible ways to preserve the plant gene bank. Tsitsin Main Botanical Garden’s in vitro collection of the genus Syringa L. includes more than two hundred accessions (species, subspecies, cultivars, and selected plants). During the research, the methods of in vitro cultivation were improved for this crop. The morphogenesis and morphometric parameters were analyzed, when cultivated lilac cultivars on the media with different growth regulators at the micropropagation stage. The analysis of growth regulators used for lilac micropropagation (6-benzylaminopurine, meta-Topolin, tidiazuron) showed that the highest values of essential micropropagation parameters (height of microshoots, multiplication rate, etc.) were obtained when cultivated on nutrient media with the addition of meta-Topolin. Murashige-Skoog medium supplemented with meta-Topolin at the concentrations of 0.5 mg/L and 1.0 mg/L was found effective for lilac micropropagation. The use of meta-Topolin in a medium induced adventitious shoot formation at the base of explants and activation of axillary buds on them. The technique of slow growth preservation was improved for the representatives of the genus Syringa. Cultivation under low light intensity (0.7 Klux) and temperature (5–7°C) on a medium added with retardant (4 mg/L of chlorcholine chloride) significantly enlarged subcultivation duration (up to 2.0 years and more) and contributed to preserving the viability of explants (81% on average).