Purpose. The adaptation of regenerant plants to environmental conditions is the final stage of micropropagation. According to a number of authors, when in vitro plants are transferred to in vivo non-sterile conditions, a significant percentage of mortality is recorded. In a previous publication, the regenerative capacity of strawberry (Fragaria vesca L.) in vitro tissues on MS culture medium (Murashige & Skoog, 1962) and a regenerants was obtained (Chornobrov O. Yu., 2019). The objective of the study is to develop an optimal protocol of acclimation of in vitro F. vesca plants to in vivo conditions. Methods. Biotechnological and statistical methods of research were applied. For the research ‘Ruiana’ and ‘Zhovte Dyvo’ cultivars were used with in vitro cultivation cycle of 30–35 days. Prepared plants were planted in 0.33 L plastic contai ners, one piece in a mixture of coconut substrate and perlite (3:1). Plants were kept under high relative humidity (85–90%) conditions for 3–5 days, 6–8 days and 10–14 days. The studies were carried out in the Plant Biotechnology Laboratory of SS of NULES of Ukraine “BFRS” during 2019–2020. Results. The duration of Fragaria vesca regenerant plants exposure in conditions of high relative humidity significantly affected adaptation efficiency. The proportion of ‘Ruiana’ and ‘Zhovte Dyvo’ plants adapted to the greenhouse conditions were 47.6 ± 2.5% and 60.0 ± 1.7%, respectively, when the plants were kept for 10–14 days. A significant efficiency of plant adaptation (more than 70%) was obtained under condition of preliminarily exposure the roots of the plants in an auxin solution for 25–30 minutes with daily application of 30% solution of glycerine as foliar spray. The plants adapted to the greenhouse conditions had pigmentation characteristic of the variety, without signs of chlorosis and vitrification. Conclusions. An optimal protocol for in vitro adaptation of F. vesca cultivars to in vivo conditions was developed and viable plants were obtained. Further research will be aimed at studying the growth and development of F. vesca regenerant plants in open ground.

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.

The article features results of studying F1 hybrids of tomato inheriting productivity factors. 21 original hybrid forms and 57 F1 tomato hybrids in green-house have been studied. The efficiency of selecting genotype of valuable plants by genotype is substantiated.