Problems and prospects of in situ, ex situ, in vitro conservation of Carlina L. species in Ukraine

Abstract

Aim. The aim was to investigate the problems of in situ, and ex situ conservation of Carlina аcaulis L., Carlina cirsioides Klok, and Carlina onopordifolia Besser ex Szafer, Kulcz. et Pawl. and to optimize the conditions of their in vitro culture. Methods. The seeds of C. аcaulis, C. cirsioides, and C. onopordifolia had a pre-sowing treatment with a gibberellic acid solution (GA₃) or indole-3-butyric acid solution (IBA) in order to obtain and root aseptic seedlings. The sterilized seeds were planted in sterile Petri dishes on semi-solid Murashige and Skoog (MS) medium with decreased macro- and microsalts concentrations (MS/2) without growth regulators. For microclonal propagation of these species, we used the rosettes of 2–3-month specimens and planted them on semi-solid Murashige and Skoog medium with decreased macro- and microsalts concentrations (MS/2) supplemented with kinetin (Кin) (1–3 mg/l) and 0.1 mg/l of 1-naphthaleneacetic acid (NAA). Results. After soaking the seeds in gibberellic acid solution, the percentage of root formation of C. acaulis, C. cirsioides, and C. onopordifolia was 33.3 %, 33.3 %, and 22.2 % respectively. The pre-sowing treatment of Carlina seeds before sterilization in IBA solution at a concentration of 1000 mg/l for 2–4 h had a positive effect. The percentages of root formation of C. acaulis, C.  cirsioides, and C. onordordifolia were 2.4–4.5 times higher than that after treatment in GA₃ solution. MS/2 medium supplemented with growth regulators (NAA and Кin) was the most efficient to provide the formation of microclones. For 6 months of cultivation the formation of C. cirsioides microclones was 6.6–6.8 rosettes per seedling, for C. acaulis and C. onopordifolia plants it was 4.2–5.0 and 4.8–5.2, respectively. Soaking of Carlina microclones in indole-3-butyric acid solution at a concentration of 1000 mg/l for 1 min increased the percentage of their rooting. Conclusions. We increased the percentage of rooting of C. sirsioides and C. onorordifolia plants to 100 % and the rooting of C.  acaulis plants to 80 %. We avoided injuring the seedlings and change of IBA concentrations in the solution during sterilization at high temperatures by using the non-sterile solution of this growth regulator. The conditions for the microclonal propagation of С. acaulis, C. cirsioides, and C. onopordіfolia have been chosen. We have worked out the schemes for the rooting of in vitro microclones.