RESUMO
Abstract In this study, in vitro propagation and acclimatization of Helianthemum germanicopolitanum Bornm. plant, a local endemic in Çankırı Province (Turkey) with arid and semi-arid lands, and an endangered species taking part among medicinal and aromatic plants were accomplished, which is under-researched. In this study, three basal media [a) Murashige and Skoog b) Gamborg's B5, and c) Nitsch & Nitsch], two gelling agents (agar 7 g/L, and gelrite 2.1 g/L), eight cytokinins and eight auxin doses of plant growth regulators [a) 6-benzyladenin, b) Kinetin-(0, 0.5, 1, and 2 mg/L), c) Indole-3-butyric acid, d) α-napthaleneacetic acid-(0, 0.25, 0.5, and 1 mg/L)] prepared in 64 different combinations with 30 g/L sucrose was added to the basal media and adjusted to pH 5.7 for in vitro propagation of H. germanicopolitanum. During in vitro propagation of the plant, external and internal infections were frequently encountered and this was solved by the developed protocol. The best shoot growth (1.141 cm) and shoot length (0.572 cm) were obtained in the Gamborg's B5 medium in combination with Kinetin (0.5 mg/L)+Indole-3-butyric acid (0.5 mg/L)+gelrite. The maximum number of shoots (19.50) and the best multiplication rate (94%) were obtained in the media containing benzyladenin (1 mg/L)+Indole-3-butyric acid (0.5 mg/L) plant growth regulator in Murashige and Skoog medium solidified with agar. At the rooting stage, the maximum number of roots (30) was reached in the Murashige and Skoog medium containing gelrite and the best rooting rate (92%) with agar. A hundred plants representing the best shoot and root growth were taken to acclimatization stage, and 32 of these plants adapted to external conditions.
