Flowers Characteristics of Selected Species of Lime-Tree (Tilia spp.) in Terms of miRNA-Based Markers Activity, Mannose Expression and Biological Compounds Content

The significant healing effect of Tilia platyphyllos Scop. and Tilia cordata Mill. flowers are well known. However, the flowers of Tilia tomentosa Moench. are not suitable for harvest due to their toxic effects. To investigate the diverse background of this effect, we applied a functional miRNA-based marker, mannose expression analysis and determined the content of bioactive compounds. Out of nine tested markers, three (miR160, miR167 and miR408) provided reproducible miRNA-based loci and two of them (miR160 and miR398) enabled the acquisition of fingerprinting specific to flower and leaf samples of T. platyphyllos and T. tomentosa. The most pronounced profiling was specific for miR408 marker, the function of which is connected to plant defense and adaptation mechanisms. We confirmed the suitability of microRNA-based markers for polymorphism determination of flowers of selected species of lime-tree. The highest values of antioxidant activity, flavonoids, total polyphenols and phenolic acids content have been reached in silver linden flowers. When comparing the transcription activity of mannose in flowers, more than 30 times higher levels of mannose transcripts for the silver linden flowers was observed.

Optimization of explants in vitro sterilization protocol of some deciduous tree species

One of the methods of obtaining planting material of deciduous plants, in particular common ash (Fraxinus excelsior L.), broad-leaved linden (Tilia platyphyllos Scop.) and silver birch (Betula pendula Roth) is microclonal propagation. Asepticity of explants is a prerequisite for microclonal plant propagation. Chemical sterilization with liquid substances is mostly used for this purpose. The mode of decontamination is influenced by a number of factors, in particular the genotype of the plant. The purpose of the study was to optimize the sterilization protocol of F. excelsior, T. platyphyllos and B. pendula explants for microclonal propagation. For research, 20–30 cm of shoots isolated from 12-year-old T. platyphyllos, 10-year-old B. pendula, and 15-year-old F. excelsior in February-March 2021 were used. Plant material was cultured according to conventional methods on a nutrient medium MS (Murashige & Skoog, 1962). Biotechnological methods were used (plant tissue culture in vitro, microclonal propagation). MS Excel software package was used to process the experimental data, the mean and its standard error were calculated. One-way analysis of variance (ANOVA) was performed to analyze the effect of explant sterilization on asepsis. The expediency of keeping plant material during the day in 0.1 % solution of «Samshit»  F. excelsior and 0.3 % solution «Fundazole»  T. platyphyllos and B. pendula is shown. The sterilization protocol of experimental plants (efficiency over 50 %) was optimized by using a stepwise method using 70 % ethyl alcohol, 1.0 % and 2.0 % AgNO3 and 2.5 % and 5.0 % NaClO. The effect of the sterilization regime of experimental plants on asepsis is statistically significant at the level of 5%. To initiate the explants, a culture medium according to the MS prescription was used with the addition of 0.25 mg/L kinetin and 2.0 g/L activated carbon. Further studies are aimed at developing a protocol for direct regeneration of microshoots of F. excelsior, T. platyphyllos and B. pendula under the action of components of the culture medium in vitro.

Nemoralisation of Pinus sylvestris and Picea abies Forest Stands in the Hemi-Boreal Zone: A Case Study from Latvia

At the beginning of the 21st century, in extensively managed mature and over-mature conifer stands (Pinus sylvestris and Picea abies) in Latvia, establishment of native deciduous broad-leaved (Acer platanoides, Tilia cordata, Quercus robur and Ulmus laevis), as well as alien broad-leaved species (Acer pseudoplatanus and Tilia platyphyllos) has been observed. The establishment of deciduous broad-leaved species in coniferous stands is a process known as nemoralisation of coniferous stands, which is characterised by a large number of seedlings of broad-leaved species, young trees and the formation of a subcanopy layer in stands. Based on the age measurements of individuals of broad-leaved species trees, the establishment of some individuals into the studied coniferous stands occurred 40–50 years ago — in the 1970s–1980s. However, the predominant age of alien broad-leaved tree species in the study plots was 15–25 years, i.e. the introduction of large numbers of seedlings of these species in the coniferous stands occurred at the end of the 20th century. In this manner, in the final phase of the conifer replacement process, stable, mostly shade tolerant, mixed stands consisting of 3–4 species have formed, in which spruce is often found together with broad-leaved species.

Phytosociological analysis of noble hardwood forests (Ostryo-Tilienion platyphylli) in the Karst and its neighbouring regions (SW Slovenia)

In SW Slovenia, at Gora under Železna Vrata and Petnik gorge near Branik – both on the northern edge of the Karst, in the collapse doline Orleška Draga at Sežana and under Brkinski Rob at the contact of the Karst and Brkini Hills, we conducted a phytosociological analysis of the stands whose tree layer is dominated by Tilia platyphyllos, T. cordata, Acer pseudoplatanus, Ulmus glabra, in places also Carpinus betulus and Ostrya carpinifolia, and classified them into three associations, Corydalido ochroleucae-Aceretum pseudoplatani, Paeonio officinalis-Tilietum platyphylli and Fraxino orni-Aceretum pseudoplatani. The latter was described as a new. Also new is a secondary large-leaved lime association Lamio orvalae-Tilietum platyphylli on the sites of montane beech forests (Lamio orvalae-Fagetum) in the Čepovan valley, at the contact of the Dinaric and sub-Mediterranean phytogeographical regions of Slovenia.

Tilia sp. Seed Oil—Composition, Antioxidant Activity and Potential Use

Research on new, untapped seed oil sources is receiving increased attention. In this study, 18 different seed samples of Tilia cordata and Tilia platyphyllos from various locations in Slovenia were collected and oil was extracted. The compositions of triglyceride fatty acids and unsaponifiable compounds were determined using GC-MS, while antioxidant activity was evaluated using the DPPH method. The oil content in the seeds varied significantly, from 9.1% to 21.7%. Linoleic acid (50–60%) was found to be the predominant fatty acid, followed by oleic acid (18–22%) and palmitic acid (8–9%). Characteristic cyclopropene fatty acids (sterculic, dihydrosterculic and malvalic acids) were present in the average range of 4–8.4%. Antioxidant activity ranged from 8.9% to 65.5%, and was higher, on average, for T. platyphyllos. Higher antioxidant activity was closely correlated with higher γ-tocopherol contents. Statistically significant correlations were confirmed between antioxidant activity and γ-tocopherol, between Δ-tocopherol and phytol, between stigmasterol and β-sitosterol and between squalene and malvalic acid. Tilia oil may be of great interest for cosmetic and dermal preparations. It is, however, not considered a good source of dietary fatty acids due to the undesired, significant content of omega-6 fatty acids.

Dendrocenosis of the Bila Tserkva national agricultural university main building courtyard: diversity, age and condition

The paper reveals the results of taxonomic assessment, phytosanitary monitoring and general condition of the dendrocenosis the BNAU main building the courtyard. It is established that the age structure of plantations ranges from 10 to 80 years, with 60 years old plants to make 12 %. The group of woody plants aged from 41 to 50 years is most numerous (33 % of the total number of trees); the larges number of shrubs ages 16–20 years (6 %). The structure of the dendrocenosis of the courtyard is formed by species of woody plants, the share of their participation ranges from 5.8 to 15 % of the total number of trees: Aesculus hippocastanum L. (15 %), Acer platanoides (9.2 %), Catalpa bignonioides Walt. (7.5 %), Populus tremula L. (6.7 %), Juglans cinerea L. (6.7 %), Ulmus glabra Huds. (6.7 %), Tilia platyphyllos Scop. (5.8 %). According to the life forms of plants, the dendrocenosis is represented by trees (81.7 %) and shrubs (183.%). The taxonomic assessment of the dendrocenosis reveals that that 120 specimens of shrubs are represented by 27 species, grouped into 23 genera of 17 families of 12 orders of 2 divisions. Magnoliophyta predominates in terms of species diversity, which is represented by 24 species from 20 genera of 16 families of 11 orders. According to the number of specimens represented by families, they can be ranked as follows: Sapindaceae Juss. > Juglandaceae DC. ex Perleb> Malvaceae Juss. > Bignoniaceae Juss. > Ulmaceae Mirb. > Salicaceae Mirb. > Oleaceae Hoffmanns. & Link> Anacardiaceae R.Br. > Fabaceae Juss. > Adoxaceae E.Mey. > Paeoniaceae Raf. According to the number of woody plants, the relative living condition of the dendrocenosis is 75 %, which characterizes the weakened condition of the stand of the BNAU main building courtyard. The best living condition was observed in 46 % of the species stand such as Picea abies L., Pinus sylvestris L., Pseudotsuga menziesii (Mirb.) Franco, Fraxinus excelsior L., Styphnolobium japonicum L., Carpinus betulus L., Rhus typhina L., Acer negundo L., Tilia cordata Mill. Under the influence of various biotic and abiotic factors, 26 % of shrubs are in a weakened state, 17 % are severely weakened, 11 % are withered. Key words: dendrocenosis, tree-shrub vegetation, species, genus, family, living condition.

Novel Piperidine and 3,4-dihydro-2H-pyrrole Alkaloids from Tilia platyphyllos and Tilia cordata Flowers

Lime flowers, traditionally used for medical purposes for the treatment of symptoms of the common cold and mental stress, consist of the dried inflorescences including the floral bracts of Tilia cordata, Tilia platyphyllos, Tilia × vulgaris, or mixtures thereof. During phytochemical investigations, 6 different alkaloids – not described until now – were detected in T. cordata and T. platyphyllos flowers. They have been isolated and characterized as alkaloids with a dihydro-pyrrole and a piperidine substructure, respectively. Compounds 1a and 1b (tiliines A and B) are characterized as 2 diastereomers containing a 2-methyl-3,4-dihydro-2H-pyrrol-3-ol, connected via a C-10 alkyl chain to a O-glucosylated hydroquinone moiety. Compounds 2a and 2b (tiliamines A and B) are diastereomers of a 2-methyl-substituted piperidin-3-ol, coupled via a C-9 alkyl chain again to an O-glucosylated hydroquinone moiety. Compounds 3a and 3b (tilacetines A and B) are 3-O-acetylated derivatives of tiliamines. Quantification of the 6 alkaloids by HPLC-ESI-qTOF analysis indicated the presence of all alkaloids in T. cordata flowers and T. platyphyllos flowers, bracts, and leaves, with tiliines A and B and tilacetines A and B being the major compounds. Acetone/water turned out be the best extraction solvent for the alkaloids, but ethanol and ethanol/water mixtures also can be used for effective extraction. Furthermore, the alkaloids are found in hot water extracts, which are typically used in the traditional medicine.

Toxicological and anti-tumoral effects of a Linden extract (Tilia platyphyllos Scop.) in HPV16-transgenic mouse model

Tilia platyphyllos Scop., is a popular broad-leave tree, native to central and southern Europe. Hydroethanolic extracts rich in phenolic compounds obtained from T. platyphyllos Scop. showed in vitro antioxidant, anti-inflammatory...