In vitro preservation of the valuable medicinal and forage plant Rhaponticum carthamoides under slow-growth conditions

Abstract

Background and Aim. The conservation of rare and economically valuable plants, including Rhaponticum carthamoides, requires the development of effective in vitro storage methods. The aim of this work is to optimize medium-term storage conditions for maral root cultures using biotechnological approaches.
Materials and Methods. Adventitious microshoots were cultured on ½ MS medium supplemented with abscisic acid (2–10 mg/L) or mannitol (3–5 g/L). The cultures were stored without subculturing for 3–9 months at a temperature of 4 ± 1 °C. After storage, morphometric characteristics and viability were assessed. iPBS analysis was used to evaluate genetic fidelity between the mother plants and regenerated plants. Eight primers were used in the study.
Results. Reducing the temperature without modifying the nutrient medium did not ensure longterm preservation. Abscisic acid inhibited growth, and this effect became more pronounced with increasing concentrations. At higher concentrations, it also delayed plant recovery processes. The most effective treatment was 3 g/L mannitol, which induced growth retardation while maintaining high regenerative capacity for up to 9 months. Based on iPBS-PCR fragment analysis, genetic fidelity between mother plants and regenerants was confirmed after 9 months of storage.
Conclusion. The optimal medium-term storage regime is cultivation at 4 °C on ½ MS medium supplemented with 3 g/L mannitol, which allows preservation of the viability and morphogenetic potential of in vitro plants.