Specific Characteristics of Rhodiola rosea Growth and Development under the Photoculture Conditions

Growth and development of Rhodiola rosea L. plants (the family Crassulaceae) were compared in their natural habitat, field stands, and in photoculture. By the indices of growth and development, plants grown for 135–137 days under the intensive photoculture were shown to exceed the 3-year-old plants developed in the natural habitats and 1–1.5-year-old plants grown in the field stands. Under the photoculture, 35% of all the plants under study started flowering at the day 75–77 after seed germination. The content of salidroside in the rhizomes of the 135–137-day-old plants was 0.4–0.6% per dry weight. Following photoculturing for 245 days, rhizome weight increased 4.5-fold as compared to the 135–137-day-old plants, and the salidroside concentration reached 1.2%, the level corresponding to the maximum content of this glycoside in the plants growing in their natural habitat and exceeding by 1.5–3 times the levels observed in the plants grown in the field stands. Under the photoculture conditions, plants of R. rosea were shown to grow without the dormancy period. Several factors apparently raised the salidroside concentration in the 245-day-old plants under the photoculture conditions, including enhanced growth, absence of the dormancy period and the period of lowered temperatures; as a whole, these factors promoted the detoxification, storage, and/or transport of the primary metabolic products.