Actinidia kolomikta (Maxim) Maxim. is a winter-hardy species of the genus Actinidia Lindl., whose fruits are valued for their high content of vitamin C and other bioactive compounds. The use of biotechnological propagation methods significantly accelerates the production of quality planting materials for this crop. This study revealed the regeneration features of promising A. kolomikta cultivars. The main morphometric parameters of explants were determined in regard to the effect of different iron chelates (FeEDTA and FeEDDHA) and cytokinins (6-benzylaminopurine, meta-Topolin, and 2-izopentyladenine) in the Quoirin and Lepoivre medium. FeEDTA-supplemented media were optimal for explant culture. Meta-Topolin was found to promote the formation of adventitious microshoots at the base of explants and bud activation, which increased the multiplication rate by 1.5 and 1.7 times compared to the media with 6-benzylaminopurine and 2-izopentyladenine. The morpho-anatomical studies revealed the structural organization of assimilation tissues and the stomatal apparatus of A. kolomikta under different culture conditions (field, in vitro, and ex vitro). The stomata in vitro were round and had a larger area, lower thickness, and a lower layer number of mesophyll compared to field conditions. The transfer from in vitro to ex vitro caused gradual normalization of the leaf structure: a decrease in the stomatal number and area, changes in shape (from round to elliptical), and an increase in the mesophyll thickness.

Cryopreservation is considered to be one of the most effective methods for long-term storage of plant genetic resources, particularly for ornamental species. However, there is a very little research on cryopreservation of lilacs. In this study, for the first time the cryopreservation protocol (a variation of a pregrowth-dehydration method) was successfully applied to two cultivars of Syringa vulgaris: ‘Aucubaefolia’ and ‘Polina Osipenko’. Explants of both cultivars were able to withstand the different steps of the protocol, and high survival and regrowth percentages were obtained after exposure to liquid nitrogen (67–100% and 63–88%, respectively). The current study is mainly focused on the preculture conditions of the applied method. Based on our results, we propose the use of paclobutrazol (PBZ) with the combination of 6-benzylaminopurine (BAP) and thidiazuron (TDZ) in the preculture medium for increasing explant tolerance to subsequent dehydration and freezing. During post-LN recovery, the explants appeared morphologically normal, and after 12–16 weeks after thawing, they were propagated and cultured as normal plantlets. Therefore, the reported method is effective for long-term storage of lilac meristems and could be used to create a cryobank of achievements in lilac breeding.

Cymbidium erythrostylum Rolfe is one of the most beautiful species of the genus cymbidium which is used as a cut flower or indoor plant. However, it was registered as a rare species even in its original habitat. This study was carried out to develop a protocol for in vitro propagation of C. erythrostilum. We used protosomes obtained by the asymbiotic germination of seed on 1/2 of Murashige and Skoog nutrient medium (MS) supplemented with 1 mg/L 2-Isopentenyl adenine (2iP) as objects of study. During the multiplication stage, the number of formed protosomes on a culture medium containing 0.8 mg/L 6-Benzylaminopurine (6-BAP) was higher (3.8 ± 0.2 protosomes). During the subsequent cultivation on ½ MS medium supplemented with 2 mg/L 6-BAP and 0.5 mg/L a-naphthaleneacetic acid (NAA), the highest numbers of shoots (4.00 ± 0.19 shoots/plantlet) and leaves (4.50 ± 0.14 leaves/plantlet) were obtained. At the rooting stage under in vitro conditions, the most effective was the use of ½ MS nutrient medium with the addition of 0.5 mg/L of indolyl-3-butyric acid IBA, 1 g/l charcoal, and 50 g/l banana puree. The obtained plants were successfully adapted to a substrate consisting of bark, perlite, and peat in a ratio of 1:1:1.

The unique collection samples of the Far Eastern species of the genus Actinidia Lindley preserved in Federal Horticultural Center for Breeding, Agrotechnology and Nursery were analysed. The in vitro collection of Actinidia has been formed since 2005 in Tsitsin Main Botanical Garden of Russian Academy of Sciences and currently includes more than 40 cultivars belonging to 3 species of Actinidia: A. kolomikta (Rupr. еt Maxim) Maxim., A. arguta (Siebold et Zucc.) Planch. et Miq., and A. polygama (Siebold et Zucc.) Maxim. Easily reproducible, dependable method for clonal micropropagation of promising selected genotypes of Actinidia was optimized. It has been established regeneration features for the studied species of the genus Actinidia at the stage of micropropagation. A. kolomikta was characterized by a lower morphogenetic potential (multiplication coefficient 5.0) compared with other studied species. A. arguta and A. polygama were characterized by high multiplication coefficients, but no significant difference between them was present (8.0 and 7.7, respectively). The features of morphogenesis of male and female forms of A. kolomikta were revealed. The cultivars of the female forms had the highest multiplication coefficient (‘Universitetskaya’ 5.2, ‘Prelestnaya’ 5.2) compared with the male and bisexual forms (‘Adam’ 4.3 and ‘Dr. Szymanowski’ 4.3). The Quorin-Lepoivre nutrient medium supplemented with 6-Benzylaminopurine at a concentration of 0.5…1.0 mg L−1 was found to be effective at the micropropagation stage, and the use of β-indole acetic acid at a concentration 0.5…1.0 mg L−1 was better at the rooting stage.

Asymbiotic seed germination in vitro of 10 species of the genus Cypripedium L. is described. Several methods of seed sterilization and some modifications of Harvais, Chu and Mudge, Norstog, Malmgren growth media weretested. Adaptation ability in the open ground of the seedlings obtained in vitro was investigated. In addition, the results ofintroduction of 17 cypripedium species in Moscow region are listed.