In the article an annotated list of the flora of vascular plants is presented for the forested part of the Burkuty Plavni natural landmark. The landmark occupies an area of 350 ha in the Chalbasska arena of the Nyzhnodniprovski pisky (Lower Dnipro Sands), near the small village Burkuty  (Hola Prystan district, Kherson region). The list includes 425 species belonging to 252 genera, 75 families, 5 classes and 4 divisions. Among them, 247 species have been found for the first time in the landmark. However, we did not find 21 species, identified in the landmark earlier. The favored conditions for growth, frequency of occurrence, sozological status, and relevant, earlier references in the literature have been indicated for each species identified in the present study. The flora of the forested part of the landmark is unique in that it has a high degree of species diversity (48.1% of the flora of the Lower Dnipro sand area), though it only occupies 0.22% of the whole territory. There are 25 sozophytes among the flora (5.9 %). Another reason for the high sozological value of the flora of the Burkuty Plavni natural landmark is the mix of endemic plants and the significant share of boreal plants in their composition, i.e. northern species on the southern boundary of their range. At the present moment only a part of the landmark is included in the Oleshkivski Pisky National Nature Park (50 ha, or 14.3%). As a result, 264 species (62,1%) of the landmark flora, including seven sozophytes (Ceratophyllum tanaiticum, Dactylorhiza incarnata, Dryopteris carthusiana, Polygonatum odoratum, Potamogeton sarmaticus, Salvinia natans, Stachys officinalis) are not currently protected. These results convincingly show the inadequate protection of the floristic biodiversity of the landmark at the present stage. It is thus important to include the entire Burkuty Plavni in the Oleshkivski Pisky National Nature Park thereby protecting its important biodiversity.

In connection with the rapid development and implementation of nanotechnology in the agriculture, biology and medicine, investigation of biogenic metal nanoparticles is the topical subject that opens up the opportunities for their practical use. Growth is an integral indicator of the physiological state of plants. Their water-retaining ability is an informative marker of water metabolism and resistance of plants. In this regard, the effect of pre-sowing seed treatment with nonionic colloidal solutions of silver and copper nanoparticles on growth parameters and water regime in wheat seedlings (Triticum aestivum) of two varieties – Myronivska 808 and Renan was investigated. The response of wheat seedlings to the action of nanoparticles treatment was assessed by changing of the organs length and weight. It was expressed as tolerance index. Under nanoparticles action the length and weight of different parts of seedlings in both varieties found to be changed. Investigated nonionic colloidal solutions of biogenic metals nanoparticles act as stimulators of growth processes, in which the effect of silver nanoparticles on these indices was more effective. Pre-sowing seed treatment with metal nanoparticles has also positively influenced to water regime in wheat seedlings. Silver nanoparticles demonstrated a higher efficiency of preventing the water deficiency development in wheat seedlings of both varieties. It has been shown that pre-sowing seed treatment with nanoparticles of silver and copper stimulates growth and increases the water-retaining ability of the plant organism. This is the basis for further research and use of solutions of the most effective nanoparticles in biology and agriculture.

The article presents results of a comprehensive study of macro- and micromorphological characters of generative organs of the endangered species Linnaea borealis, which is listed in the Red Data Book of Ukraine. Morphology of pollen grains, flowers and fruits was studied using light and scanning electron microscopy. Additional characters that can be used for solving controversial issues of taxonomy of Caprifoliaceae are revealed. The flower of L. borealis is almost zygomorphic; it has five linear-lanceolate sepals connate at base, tubular, bell-shaped corolla pubescent inside with ribbon-like hairs (only on broadly ovate non-connate parts of petals); two of four stamens are longer than the other two, with filiform filaments and narrow-ellipsoidal, crescent-bent, swinging anthers; carpels with a lower, ovoid ovary, a narrow style, and a funnel-shaped stigma. For the first time we observed a flattened egg-shaped outgrowth on the apical part of the connective of stamens. Palynomorphological peculiarities of L. borealis are specified in detail: pollen grains are 3(4)-colporate, prolate, spheroidal or oblate-spheroidal in shape, in equatorial view elliptical, oval or circular in outline; in polar view slightly 3-lobate, circular-triangular or circular-rectangular; medium- or large-sized, with spinulose exine sculpture. Additional micromorphological characteristics of the fruit surface have been revealed: tuberculate structure and the presence of pubescence with simple and glandular trichomes. Three morphological groups of simple hairs (long, medium, and short ones) and two groups of glandular hairs (short with small heads and long with large heads) are distinguished. Precise localization of hairs of these groups in certain areas of fruits and peduncles is revealed.

The purpose of the study was to evaluate the contribution of salinity, irradiance, nitrate and phosphate, and their interactions into the yield of cell number and b-carotene accumulation in Dunaliella salina. To avoid confounding of the effects of factors-conditions by the depletion of factors-resources, the alga was grown in fed-batch culture. In the level ranges of the experimental factors (irradiance 2–8 klx, salinity 1–4 M NaCl, KNO₃ 0–80 mg L-1, K₂HPO₄ 0–10 mg L-1), nitrate and phosphate influenced the productivity of culture by cell number and b-carotene accumulation more strongly than salinity and irradiance. Effects of salinity and irradiance depended on nutrients and their pre-supply to the inoculum. Total effect size h² of nutrients on cell yield comprised 0,59 for non-starved and 0,43 for starved inoculum, whereas total effect size of factors-conditions – 0,10 and 0,12 correspondingly. As to cellular b-carotene content, total effect size of nutrients on the cells grown from non-starved and starved inoculum was 0,71 and 0,58, and of factors conditions – 0,8 and 0,5 correspondingly. Remained variances of cell yield and b-carotene content were attributed to the interactions of salinity and irradiance with the nutrients. The combination of high values of salinity and irradiance exerted its own, unconfounded by depletion of nutrients, but lower influence on b-carotene accumulation. The highest b-carotene content of 53 pg per cell was observed in the culture grown from the starved inoculum at the deficiency of phosphorus. Combination of high salinity and irradiance values yielded 17 pg of b-carotene per cell compared to about 5 pg under the optimal culture conditions. Controll nutrient supply would be the most powerful tool for biosynthesis control in D. salina culture.

The article summarizes the study of the Burkuty Plavni landmark bryoflora during period of 1983–2017. The landmark is located on the Chalbasy arena of the Nizhnodniprovski pisky in the southern steppe zone of Ukraine, 20–25 km from the Black Sea shore. The psamophytic steppes are dominat on the positive elements of the relief a meadows and wetlands with birch, alder, aspen and oak forests occupy of sand depression. These small forests are remnants of the Herodotus Gilea. The pine plantations are a main landscape elements aroud this landmark. Bryoflora includes 63 species of 36 genera of 23 families of Marchantiophyta and Bryophyta. 54 predominant Bryopsida species compose 79,38% of the bryoflora. The families Amblystegiaceae and Brachytheciaceae dominate with 9 and 8 species respectively (25,93%). Brachythecium, Sphagnum and Orthotrichum (8,1%) are main genera in bryoflora spectrum. Probably, boreal (29 species – 45,82%) and nemoral (23 species – 36,34%) mosses migrated along river valleys from the northern zones to the south. Bipolar (25 species, 39,5%) and holarctic (16, species, 25,28%) mosses migrated to Burkuty Plavni in last periods. Mesoxerophytes (20 species, 31,6%), helioscythophytes (33, 52,14%), incertophytes (52, 82,16%), oligomesotrophs and mesotrophs (18 species,56,88%), the flat surface biomorph (18 species,28,44%) and loose turf biomorph (16 species, 25,28%) were dominated. There are 31 species (49,2%) within synanthropic apophytic fraction. The greatest interest is caused by five species of the sphagnum mosses which were found in Burkuty Plavni landmark. The different points of the time and migration ways of the sphagnum mosses and other bryophytes to the south of Ukraine are discussed.

160 species of lichens and lichenicolous fungi have been found in Chalbasy arena in Lower Dnipro sand dunes. Absconditella lignicola, Anaptychia crinalis, Bacidia fraxinea, Ramalina canariensis were a new for the Ukrainian plains and Caloplaca monacensis, Chaenotheca chlorella, Cladonia macilenta, Heterocephalacria physciacearum, Lecanora chlarotera, Lepraria lobificans, Porina aenea, Punctelia subrudecta were firsty found for steppe zone. Among Chalbasy arena, the habitats of Burkuty plavni are hotspot for lichens and lichenicolous fungi diversity of the steppe zone of Ukraine. The landscape is cover of 0,5% of Lower Dnipro Sand dunes and has 77% lichens and lichenicolous fungi founding on this territory. The Chalbasy arena represents a northern lichen elements. It occupied of the sand dunes habitats after the last glacial period 10–12 thouthand years ago. Probably, Absconditella lignicola,Candelariella kuusamoensis, Punctelia subrudecta,Usnea glabrescens are relics of the early Holocene. Probably, the penetration of Atlantic species, Anaptychia crinalis,Athallia alnetorum, Bacidia fraxinea, Candelaria pacifica, Ramalina canariensis to the territory of Lower Dnipro sand dunes habitas began in the second half of the Holocene and it continues to this time. In Chalbasy arena, Cetraria aculeata, Ramalina canariensis, Xanthoparmelia camtschadalis are listed in the Red Data Book of Ukraine and Anaptychia ciliaris,Bacidia rubella, Candelaria concolor, Chaenotheca trichialis, Flavoparmelia caperata, Lecania ephredrae, Parmelina quercina, Parmelina tiliacea, Placynthiella olygothropha, Phlyctis argena, Usnea hirta, U. glabrescens are included to the Red List of Kherson region. Absconditella lignicola, Anaptychia crinalis, Athallia alnetorum, Bacidia fraxinea,Candelaria pacifica, Cladonia macilenta, Caloplaca monacensis, Lepra albescens, Chaenotheca chlorinа, Porina aenea, Pseudoschismatomma rufescens, Punctelia subrudecta are vulnerable lichen species within steppe zone and are in need of protection. It is proposed to expand the territory of the Oleshkivski pisky National Park  and create a Gileya Regional Landscape Park  on western part of Chalbasy arena with aim to protect of the lichen habitats.

The mycological researches of aphyllophoroid fungi completed at Ichnia National Nature Park (Ichnia district, Chernihiv Region, Ukraine) resulted in discovering Postia ptychogaster, which is a new polypore species for mycobiota of Ukraine. This species was found at different stages of development on fallen branches of Picea abies, which is the most favorable substrate for the species development. This species inherent feature is ability to form the anamorphic stage, preceding development of the teleomorphic stage. Such phenomenon is rather unusual for the species of Polyporales. The macro- and micromorphological features were provided for the study specimen, both of the anamorphic and the teleomorphic stages, with the original photos and figures thereof attached. We have also discussed the ecological peculiarities and the general distribution of P. ptychogaster in the world. We have found out that cenooptimum of this species is located within the coniferous forests zone. This assumption is supported by the fact that this species is the most common in the Northern European countries. In the Central Europe this species occurs less often, where all over the Southern European countries it has been record in Italy only. Most likely, in the mixed forests zone P. ptychogaster is located on the eastern boundary of this species natural area. We managed to find it in the Forest Steppe. Whereas, Ichnia national nature park is located on the northern part of the Forest Steppe, immediately adjacent to the mixed forests zone, probably, the substrate necessary for P. ptychogaster development was available there. Presumably, the foregoing species can be also found in the other districts in the mixed forests zone and in the northern Forest Steppe of Ukraine. However, new specimens should be search for to prove this assumption.