Features of Seasonal Rhythms of Growth and Development of Representatives of the Genus Coreopsis L. and the Accumulation of Antioxidant Substances in their Infloresences

The article presents the results of a study of the growth and development characteristics of five studied representatives of the genus Coreopsis L. – C. basalis (A. Dietr.) S.F. Blake, C. grandiflora Hogg. ex Sweet., C. grandiflora cv ‘Plena’, C. lanceolata L., C. major Walt. growing in the open ground conditions of the Nikitsky Botanical Garden. The content of dry matter, ascorbate and carotenoids in the inflorescences of these plants was determined. It was established that the studied representatives of the genus Coreopsis, under the conditions of introduction on the southern coast of Crimea, undergo a full growth and development cycle, including flowering and fruiting. In the species C. basalis, C. grandiflora and the variety C. grandiflora cv ‘Plena’, repeated phases of “budding” and “flowering” occur, followed by the onset of a repeated phase of “fruiting”. The key value of biological minimum air temperature from +5.0ºC, necessary for the onset of the growing season in plants and the onset of the generative development phases, has been determined. The sums of active air temperatures accumulated by the onset of the following phases have been established: "budding" (from 696.9ºC to 2271.8°C), "flowering" (from 1068.2ºC to 1301.2ºC), "fruiting" (from 1694.0ºC to 2568.8ºC) for different representatives of the genus Coreopsis. The highest concentration of ascorbic acid and carotenoids in inflorescences was observed in C. grandiflora cv. ‘Plena’, C. lanceolata, C. basalis. C. lanceolata and C. major were distinguished by a high dry matter content. Thus, the studied species of the genus Coreopsis – C. basalis, C. grandiflora, and C. lanceolate – are better adapted to ecological and climatic conditions. Due to the relatively high content of carotenoids and ascorbic acid in the plant material of these plants, they can be considered promising crops for the pharmaceutical industry. It should be noted that further in-depth study of certain pharmacological indicators, as well as the economically valuable agronomic traits of the above-mentioned species, is advisable, with the subsequent potential use of coreopsis plant material in the pharmaceutical industry.