Method of propagation, stimulation of rhizomes growth <em>in vitro</em> culture and adaptation in the open ground for the genus <em>Miscanthus </em>representatives

Purpose. To develop a method of propagation, stimulation of rhizomes growth in vitro culture for the genus Miscanthus representatives and their adaptation in the open field without the use of greenhouse complexes for acclimatization and completion of growing. Methods. Biotechnological procedures, mathematical and statistical analyses. Results. Prescription of nutrient medium was developed for explants inoculation, sprouts propagation, rhizomes growth stimulation in vitro. Such sterile explants as seeds, buds to be removed from rhizomes, parts of  stems with bud were placed on modified media with mineral portion by Murashige and Skoog (MS) that contained 0,5–1 dose of macroelements and one dose of microelements,  vitamins (10 mg/l of thia­minum, 1,0 mg/l of pyridoxine, 1,0 mg/l of nicotinic acid and 1,0 mg/l of ascorbic acid) supplemented with amino acids (250 mg/l of glutamic acid, 3 mg/l of tyrosine, 3 mg/l of arginine, 2 mg/l of hydroxyproline), plant growth regulators [0,5–1,0 mg/l of GA (gibberelline acid), 0,2 mg/l of 6-BAP (6-Benzylaminopurine, 0,1 mg/l of NAA (α-naphtylacetic acid)] in different variations. After seed germination, buds emerging and sprouts formation 1–2 cm in height, for propagation purpose they were passivated on the medium of other composition that differed from previous one by the content and ratio of growth regulators, especially by a high concentration of cytokinins [6-BAP (0,4–0,5 mg/l), kinetin (0,5 mg/l), adenine (0,5 mg/k)] in different variations in presence of GA (0,2 mg/l). In order to stimulate rhizomes growth, microclones were transferred on media with other composition and ratio growth regulators (6-BAP (0,2–0,3 mg/l) + GA (0,5–1,0 mg/l) or 6-BAP (0,2–0,3 mg/l) + GA (0,5–1,0 mg/l) + NAA (0,1 mg/l),  in other words,  with a high content of gibberellins. After the formation of rhizomes 10–15 cm in length, miscanthus plants were planted out in the open ground. Stimulation of rhizomes initiation and elongation on appropriate nutrient media before Miscanthus giganteus, M. sacchariflorus and M. sinensis planting in vivo resulted in 100% adaptation and 100% survival of plants in the winter period without the use of greenhouse complexes. Conclusions. The method of miscanthus propagation in vit­ro and adaptation in the open ground was developed that included stimulation of rhizomes growth and favoured the increase of their length on media supplemented with gibbe­relline that guaranteed 100% preservation of microplants to be propagated from in vitro culture during adaptation in the open ground and acclimatization in winter.