The article presents data on the content and composition of petitgrain essential oil of six varieties and hybrids of lemon growing in open ground in a humid subtropical climate (Republic of Abkhazia): Citrus limon (L.) Osbeck'Odishi', C. limon 'Large-fruited', hybrids C. limon 24517 and 31375, small-fruited limetta ( Citrus limetta Risso) and sweet lemon ( C. limetta 'Chontipico'). The leaves of the studied varieties contain from 0,18 to 0,42% of essential oil (wet weight) straw-colored with lemon aroma. In the essential oil of the 'Large-fruited' variety, hybrid 24517 and small-fruited lime, citral isomers and D-limonene predominate, which cause a pronounced lemon aroma of the oil. The 'Odishi' essential oil has a lemon-pink aroma with floral notes, which is explained by the predominance of citronellal and citronelol in it. Sweet lemon petitgrain oil has similar floral notes, with linalool and citronellal as the major components. A mixed lemon-floral-woody aroma is possessed by the essential oil from the leaves of hybrid 31375, in which, in addition to citral and linalool, sabinene is present. The 'Large-fruited' variety is characterized by the highest content (0,42%) and quality of petitgrain oil.

The article presents the results of long-term research on the adaptive potential of plants of the genus Iris of the family Iridaceae in the Northern forest-steppe of Western Siberia. An assessment of the morphobiological features of irises was carried out, the timing of flowering and the amount of positive temperatures necessary for the onset of such phenological phases of development as regrowth, budding, flowering and fruiting were determined. The indicator role of phenolic compounds and peroxidase in iris leaves during seasonal development was revealed. The studied indicators can be used as an informative parameter for evaluating the state of plants for phyto-indication and introduction.

The results of the ascorbic acid content in the fruits and leaves of 10 persimmon cultivars from the Nikitsky Botanical Gardens’ collection are presented. It has been established that the concentration of ascorbic acid in technical persimmon fruits is 19,8-56,3 mg / 100 g, and in mature fruits it is 70-85% lower (5,08-8,96 mg / 100 g). Persimmon leaves contain 5-20 times more ascorbic acid than in fruits. The results showed the ability to use persimmon leaves as an additional source of vitamin C. The maximum content of ascorbic acid is allocated to the fruits of the cultivars Virginskaya Krupnoplodnaya, Delishes, Sidles and leaves of the cultivars Sidles and Zolotistaya.

In connection with the study of the effect of the succulent seed coat (sarcotesta) of Jasminum fruticans L. (Oleaceae) on the viability of seeds, a study of the germination of test objects at different volume concentrations ( σ_В ) of mature seed extract was conducted 1; 0,75; 0,5; 0,25. The test objects were radish seeds ( Raphanus sativus var. radicula Pers.) ‘Zhara’ and watercress ( Lepidium sativum L.) ‘Zabava’ (Brassicaceae). The seeds were seeding on distilled water as the control. The volume content of phenolic compounds in the obtained extract solutions of various dilutions was determined. A qualitative reaction to tannins contained in J. fruticans seed extract was performed. The qualitative reaction confirmed the presence of a condensed group of polyphenolic compounds in the extract. A decrease in the germination of radish and watercress seeds was found at extract concentrations of 0,25 (0,31 mg/ml PC), 0,75 (0,92 mg/ml PC) and 1 (1,22 mg / ml PC). When σ_В =0,50 (0,61 mg/ml PC), the germination of radish and watercress increases, but the indicators do not have a statistically significant difference compared to the control. It is shown that the formation of abnormal sprouts of test objects increases with an increase in the volume concentration of the extract, with the exception of the variant σ_В =0,50. Radish has more than 60% of abnormal seedlings are associated with hypocotyl deformation. Watercress seedlings have hypocotyl abnormalities and root abnormalities (more than 50%) The observed pattern of changes in the germination of test objects seeds from the concentration of J. fruticans water seed extract indicates its allelopathic properties. The presence of phenolic compounds in the sarcotesta of J. fruticans indicates its regulatory function in the process of seed development.

The development of the extractive industry on the territory of the Crimean Peninsula leads to an increase in the number of quarries and, consequently, to an increase in the area occupied by disturbed lands requiring recultivation. The reclamation of such land plots on the basis of creating the necessary conditions for the development on them of regenerative successions of zonal vegetation and ultimately the formation of soils is much cheaper for land users. Therefore, studies of the rates of soil formation, including using the methods of mathematical modeling of the processes of formation of the humus horizon of the soil over time, become relevant. Based on the example of the Alexandrovsky field of saw limestone in the Black Sea region of the Republic of the Crimea, the economic efficiency of reclamation of disturbed land was calculated. The results of the calculation showed that in terms of cost-effectiveness, it is more rational to use the mining engineering model with further self-overgrowing of the sites to be reclaimed when it comes to reclaiming disturbed lands of the Alexandrovsky career.

Forest is one of the most effective ways for mitigating elevated CO² concentration in the atmosphere. The ability of Pinus sylvestris to grow in A1 arid conditions was studied. The accumulation of flavonols and proanthocyanidins in the pine-needles, periderm and phloem of shoots has been established. Resistance to diseases and pests depended from the structure characteristics of the polymerized form of catechins (proanthocyanidins). These compounds are capable to use UV-B waves for their synthesis and show very high antioxidant activity. The advantages of pine for creating of a band of trees compared to poplar species are discussed.

The inventory of the current status for the ornamental perennials collection of Institute Botanic garden UB RAS with clarification of composition and conservation status of the samples was carried out. A total of 213 red-book listed species (112 genera from 42 plant families) revealed to document the flora. The most valuable specimens of rare declining in number plants and endangered (under threat of extinction) species are noted

The article presents for the first time the results of a study of the preservation features of explants of 2 rare endemic species under the conditions of the in vitro genebank for 12 months. Microshoots of Crepis purpurea (Willd.) M. Bieb (Asteraceae) and Scrophularia exilis Popl. (Scrophulariaceae), cultured in vitro were included in the research. Microshoots’ segments 0,5-1,0 cm long were used as explants for preservation. The explants were placed on an agarized culture medium with a recipe of ¼ MS supplemented with growth inhibitors: 0,2 g/l CCC chlorocholinchloride (BASF, Germany) and 60 g / l sucrose (Panreac, Spain). As a control, a medium of ¼ MS was used, supplemented with 60 g / l sucrose without retardants. Culture vessels were placed in refrigerators with a light intensity of 1.25-3.75 mcM m^-2 s^-1 and a temperature of 4, 6, 8, 10 and 12,0°C. Plant material was evaluated after 6 and 12 months of cultivation using qualitative and quantitative characteristics of explants. It was found that the preservation of viability and reduction of growth kinetics of Crepis purpurea and Scrophularia exilis explants during 12 months of deposition in the in vitro genebank, along with low illumination intensity and the use of a nutrient medium with growth inhibitors, was facilitated by exposure to a temperature of 4,0-6,0°C. Conservated explants of the studied genotypes after transferring to standard cuture conditions the morphogenetic potential and the ability to regenerate microshoots and microrosettes were remained.

The article is characterized of Scilla siberica in the Donbass region’s flora (systematic position, geographic, eological-cenotic and biomorphological features, population structure). It was the first time, when we discovered Scilla siberica with purple flowers in Donbass (var. phoeniceum Gryt. (prov.)). We studied the chorology of the species and spread mapping of Scilla siberica was made. We found out that Scilla siberica grows in 146 locations (67 of these locations were found by author). We also came to the conclusion that Scilla siberica occurs everywhere and do not need personal protection.

Based on the research carried out in 1995-2019, the main approaches to the selection of criteria for attracting introduced species in the dry conditions of Khakassia are substantiated. The objects of research are 14 species of medicinal plants of the family Lamiaceae Lindl. different areas of origin. During the introduction, we used the method of comparing climates and generally accepted research methods. The most promising sources of source material are species that have Euro-Asian, Siberian-Central Asian, and North American ranges; by belt-zonal type - forest-steppe, mountain-steppe boreal; by ecological type - species from the group of mesoxerophytes, xeropetrophytes that have wide ecological amplitude, the requirements of which correspond to the conditions of the sharply continental climate of Khakassia.

The observations were carried out in the Botanical garden of the Petrozavodsk state University, located in the taiga zone. Objects of research served 1 native and 5 introduced species: Picea abies (L.) Karst., P. obovata Ledeb., P. mariana Britt., P. glauca (Mill.) Вritt., P. pungens Engelm., P. omorica (Pane) Purk. The study of morphogenesis in vegetative buds was carried out axial shoots from the middle part of the crown since the beginning of the bud swelling until the cessation of laying primordial needles (May to September). The growing shoots are cut off after 2-3 days and were fixed in a mixture of alcohol and glycerin. For the start date of a stage, took the time when it was noted in not less than 30% of the buds. It is established that intrarenal development of vegetative organs from the native species P. abies was studied and introduced species of the genus Picea characterized by similar phases: rest, laying cover scales and laying primordial needles. Morphogenesis of vegetative buds of P. abies on the timing ahead of the development of the bud in the introduced species, which indicates a much greater insistence of the latter to temperature. The duration of the morphogenesis of the buds in all studied types varies slightly (days 131-137). However, the morphogenesis of vegetative buds of native species for 1-4 weeks ahead in terms of development of the buds in introduced species with a similarity of morphogenesis of the bud (P. abies and P. glauca), the value of the annual increment of the shoots is almost the same.

The regenerative capacity of Echinacea hybrid cultivar Mama Mia and the selected somaclonal variegated variant at the propagation and rooting stages was compared. The influence of the 6-BAP concentration in the MS culture medium on the microrosette formation at the propagation stage was studied. The highest morphogenetic potential of the selected form in comparison with the cultivar Mama Mia was found. It was shown that ½ MS culture medium supplemented with 0.3 mg/L IAA was the optimal medium for effective development of the root system of the genus Echinacea representatives at the rooting stage.

Seed productivity of 22 early flowering plants of the natural flora of the Kamensky geobotanical region, introduced into the culture and used in landscaping, has been established. It was shown that the actual average seed productivity of one individual of various plant species varies from 12 to 373 pcs., And the maximum - from 20 to 448 pcs. seeds, which is 10 to 90% of the potential. In most species, high actual seed productivity is combined with high potential productivity. Field germination of seeds of all plant species was higher when sowing with freshly harvested seeds within 5-14 days after ripening. Storage of seeds at a temperature of 18,0-20,0ºС followed by sowing them in the spring led to a significant decrease in germination.

The results of studying maples of the Palmata section in the South-Ural Botanical Garden-Institute are presented. It is established that in the open ground «Japanese maples» do not preserve the natural form of growth; they are in a weakened state of life. The winter hardiness of A. circinatum is III-IV, A. pseudosieboldianum - III, and A. palmatum when sheltering for the winter is II (III) points. In the greening of the region can be used in covered ground conditions; in container culture; in open ground with shelter for the winter A. palmatum , without shelter A. circinatum and A. pseudosieboldianum ; cultivars A. palmatum - only in container culture.

The taxonomic composition of the genus Chaenomeles L. was determined in the conditions of the Sochi Black sea region. Morphological and biological description was made and fruiting was evaluated for 19 taxa. Decorative cultivars Ch. japonica, Ch. speciosa, Ch. × superba, Ch. × vilmoriniana are of interest for cultivation in the humid subtropical zone of Russia. Fruit cultivars are not represented. Ch. sinensis is recommended as a fruit crop of Chaenomeles and a promising form of Ch. × superba has been identified. The cultivar Ch. speciosa ‘ Kermesina ' is universal and recommended for use in both gardening and fruit growing.

The assessment of decorative value of 35 peony cultivars growing in the Botanical garden plantings (Ekaterinburg, Sverdlovsk region, the Central Urals) were presented. For assessment were used a 100-rating scale which included the following features: flower colour, flower size, flower shape, flower doubleness, peduncle strength, bush decorative value, flowering abundance, blooming duration, flower scent, plant distinction, plant condition. The obtained assessments were compared to the literature data to examine for compliance with the main flower characteristics of peony cultivar and to reveal distinguishing features for peony plants in Sverdlovsk region and the Central Urals. As a result, 23 peony high-opportunity cultivars and 12 appreciable cultivars were distinguished and recommended for landscape gardening in Sverdlovsk region. For high-opportunity peony cultivars introduced in the Central Urals a descriptive characteristic based on the main flower decorative features was compiled.

The article presents the research results of the genesis of the elements of the microsporangium wall, sporogenous tissue, microspores, megaspores, male and female gametophytes of the Platycodon grandiflorus . The types of formation of the structures mail generative sphere (dicotyledonous type of microsporangium wall formation, simultaneous type of the tetrad microspores development, 3-cells of the pollen grains with 6-th pores, Polygonum - type of the formation embryo sac) have been established. A high viability of pollen grains was established during pollination and possibility of obtaining complete seeds when growing this species in the conditions of the Southern Coast of the Crimea.