Conservation of the vulnerable species Oxytropis chankaensis (Fabaceae) using in vitro culture

The protocol of microclonal reproduction of Oxytropis chankaensis Jurtz. (a rare endemic species of the Primorye Territory) was developed for the first time. Seeds of the second year of storage were used as primary explants. Seed germination was 36%, and viability – 75%. Cultivation was carried out on Murashige and Skoog (MS) medium. The effect of four growth regulators (6-benzylaminopurine, thidiazuron, 1-naphthylacetic acid and indolе-3-butyric acid) in concentrations from 0.5 to 2 mg/l, and of their combinations on the reproduction index and rooting of microclones in vitro was evaluated. In the studied species, the positive effect of 0.5 mg/l thidiazuron and 2 mg/l indole-3-butyric acid on the multiplication of shoots was observed. On the growth media supplemented with the above growth regulators, the reproduction index was 6 and 7, respectively. Simultaneous application of two growth regulators into the nutrient medium leads to the formation of callus tissue, subsequently vitrified. Root formation is observed on MS medium supplemented with 1 mg/l indole-3-butyric acid or 0.5 mg/l 1-naphthylacetic acid.