Arbutus Unedo Research Articles

Stem Growth and Dehydration Responses of Mediterranean Tree Species to Atmospheric and Soil Drought.

Stem growth responses to soil and atmospheric drought are critical to forecasting the tree carbon sink strength. Yet, responses of drought-prone forests remain uncertain despite global aridification trends. Stem diameter variations at an hourly resolution were monitored in five Mediterranean tree species from a mesic and a xeric site for 6 and 12 years. Stem growth and dehydration responses to soil (REW) and atmospheric (VPD) drought were explored at different timescales. Annually, growth was determined by the number of growing days and hours. Seasonally, growth was bimodal (autumn growth ≈ 8%-18% of annual growth), varying among species and sites across the hydrometeorological space, while dehydration consistently responded to REW. Sub-daily, substantial growth occurred during daytime, with nighttime-to-daytime ratios ranging between 1.2 and 3.5 (Arbutus unedo ≈ Quercus faginea < Quercus ilex < Pinus halepensis in the mesic site, and Juniperus thurifera < P. halepensis in the xeric site). Overall, time windows favourable for growth were limited by soil (rather than atmospheric) drought, modulating annual and seasonal growth in Mediterranean species, and stems maintained non-negligible growth during daytime. These patterns contrast with observations from wetter or cooler biomes, demonstrating the growth plasticity of drought-prone species to more arid climate conditions.

Analysis of landscape structure changes in Marmara Lake and its surrounding area using remote sensing data

This study investigates temporal changes in the landscape structure of Lake Marmara (Gölmarmara, Manisa, Türkiye), a designated bird sanctuary and registered wetland, over 10 years period using remote sensing techniques. The analysis employed the Normalized Difference Vegetation Index (NDVI) on satellite imagery from 2015 and 2024, processed through the ArcGIS/ArcMap software, to assess landscape metrics within the study area. The Normalized Difference Water Index (NDWI) was also utilized to evaluate the interactions between the water body, wetlands, and their surroundings. The findings were further supported by surface temperature analysis (STA) and comparative data. NDVI analysis revealed a 39.38% reduction in the Lake Marmara water body, an 11.09% decrease in forested areas, and an 8.28% decline in tree/shrub areas over 10 years. The dominant tree species in the forest vegetation was Pinus brutia, while other prevalent species included Quercus coccifera, Cistus creticus, Pistacia terebinthus, Pistacia lentiscus, Arbutus andrachne, Arbutus unedo, Olea europaea, Erica arborea, Phillyrea latifolia, and Sarcopoterium spinosum. Conversely, residential areas expanded by 21.21%, and agricultural areas increased by 4.11%. NDWI analysis indicated a 14.46% reduction in moderately dry areas and a 41.92% increase in dry areas. Furthermore, surface temperature data showed an increase over the 10 years. This study is expected to contribute significantly to the field by providing insights into sustainable land use and planning strategies. It offers a comprehensive perspective on wetland management and conservation of biological diversity by elucidating the temporal and spatial relationships between wetlands and their environment, considering both ecological and anthropogenic factors.

Valorization of Strawberry Tree Berries and Beeswax from Montesinho Natural Park for Cosmetic Industry-A Case Study Formulation.

Consumers are increasingly concerned about cosmetic ingredients' origin, looking more than ever to sustainable and greener formulations. The Natural Park of Montesinho, located in Portugal, is characterized by an enormous fauna and flora diversity. Among them, beeswax and strawberry trees (Arbutus unedo) have attracted the cosmetic researchers' interest due to their bioactive compounds' richness, particularly fatty acids and phenolic compounds. The main goal of this study was to develop an innovative cosmetic product with antioxidant properties composed by both matrices. Briefly, samples were obtained in the Natural Park of Montesinho in October 2022. Beeswax was analysed for lipid profile and contaminants, while extracts were obtained from fruits by ultrasound-assisted extraction (UAE) using water as a solvent. The effect of extraction time (15-90 min) was studied on the total phenolic content (TPC), in vitro antioxidant/antiradical activity, and reactive oxygen species (ROS) scavenging capacity. The beeswax lipid profile presented a high incidence of palmitic, oleic, and linoleic acids. The extract obtained at 60 min presented the highest TPC (30.27 mg GAE/g dw) and antioxidant/antiradical activities (ABTS = 30.36 mg AAE/g dw; DPPH = 43.83 mg TE/g dw; FRAP = 415.61 µmol FSE/g dw). An IC50 of 19.78 µg/mL was achieved for the hypochlorous acid, while for superoxide radical and peroxyl radical the IC50 were, respectively, 90.51 µg/mL and 0.19 µmol TE/mg dw. The phytochemical profile revealed a high content of gallic acid, and catechin and its derivatives. The hydrophilic cream developed revealed ideal technological parameters, particularly its stability.

Effects of Strawberry Tree (Arbutus unedo L.) Aqueous Leaf Extract and Arbutin on PK-15 and HepG2 Cells.

The antioxidant properties of the leaves of the Mediterranean strawberry tree (Arbutus unedo L.) are mainly attributed to the main bioactive compound, the phenolic glycoside arbutin. In this study, the safety profile of strawberry tree aqueous leaf extract (STE) and arbutin at the DNA level was assessed in vitro using porcine PK-15 kidney cells and HepG2 cells derived from human hepatomas. To examine the effects on cell viability and DNA damage, cells were treated for 24 h with STE or arbutin at three concentrations presumed to be non-toxic (400, 200, and 11.4 µg/mL). Assessments were performed using the MTS viability assay, dual acridine orange/ethidium bromide fluorescent staining, and alkaline comet assay. Results showed that the highest concentration (400 µg/mL) of both tested compounds had no significant cytotoxic effects on either PK-15 or HepG2 cells. Apoptosis was the predominant type of cell death and the total amount of DNA damage in treated cells was within acceptable limits. These results on the in vitro cytocompatibility of arbutin and STE with PK-15 and HepG2 cells could serve to make more reliable judgements about safe levels of arbutin in cosmetic products and functional foods, given the increased popularity of the compound in recent years.

Biogenic synthesis of MgO nanoparticles using Arbutus Unedo leaf extract for removal of Bemacid Red from wastewater: Optimizing using BBD-RSM and ANN approach

Magnesium oxide nanoparticles were synthesized using leaf extracts from the Arbutus unedo plant through a sustainable and eco-friendly green synthesis approach. The efficacy of magnesium oxide nanoparticles in removing Bemacid Red dye was assessed by optimizing the removal process using a synergistic approach of artificial neural network and response surface methodology. Magnesium oxide nanoparticles were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and X-ray fluorescence, confirming their well-defined crystalline structure, successful synthesis of pure MgO with an average particle size of 12.22 nm, and excellent thermal stability. Removal efficiency of 98.34 % was achieved at an adsorbent mass of 0.5 g. L−1, a temperature of 25 °C, an initial dye concentration of 80 mg. L−1, and a contact time of 20 min. The Langmuir adsorption model was selected to describe the adsorption of Bemacid Red onto the surface of magnesium oxide nanoparticles with an R2 value of 0.98, showing a maximum adsorption capacity of 632.91 mg. g−1. These findings underline the potential of magnesium oxide nanoparticles for sustainable wastewater treatment applications in various industrial sectors.

Effects of Strawberry Tree Water Leaf Extract and Arbutin on Biochemical Markers and DNA Integrity in Brain Cells of Lewis Rats.

There is growing evidence that arbutin and plant extracts rich in arbutin, such as extracts of the strawberry tree (Arbutus unedo L.), exert a range of beneficial effects, including cyto- and genoprotective properties. This study evaluated the effects of strawberry tree water leaf extract (STE) and arbutin in the brain tissue of Lewis rats. STE or arbutin were administered per os to male and female rats at a dose of 200 mg/kg body weight/day for 14 or 28 days. Treatment outcomes were evaluated using biochemical markers (lipid peroxidation and the activities of the antioxidative enzymes catalase and superoxide dismutase). The effects of the tested substances on DNA integrity in brain cells were evaluated using the alkaline comet assay. The results suggest a high biocompatibility of both tested substances with rat brain tissue. No significant harmful disturbances were observed in the oxidative/antioxidative status or impairments of DNA integrity in the rat brain cells. Nearly all post-treatment values were within tolerable limits as compared to the matched control rats. Such encouraging findings support further research using other subtle biomarkers to clarify the safety aspects of arbutin and STE prior to the development of specific nutraceutical products.

Effect of climate change on current and future potential distribution of Strawberry tree (Arbutus unedo L.) in Türkiye

The demand for nontimber forest products (NTFPs) has increased significantly in recent years. Hundreds of plant species that grow naturally in Türkiye have medicinal and aromatic value. Medicinal and aromatic plants are primarily used as a sources of tea, spices, condiments and essential oils. Species belonging to the genus Arbutus L. are used for decorative purposes and as fuel wood in many wood-based industries, they also have a wide range of uses in packaging, chairs making and furniture production. Additionally, the fruits of these trees are widely consumed by humans and animals because they are rich in sugar and vitamin C. It is predicted that changes in climatic conditions will significantly change the distribution, composition and function of forests threatening biodiversity. The purpose of this study was to model current and future potential geographical distributions of Arbutus unedo L., which is among the species that naturally grow in Türkiye and is of substantial value in terms of its ecological contribution to forest ecosystems, based on species presence data and environmental variables (bioclimatic variables and altitude). The current and future distribution area models for Arbutus unedo L. indicate that the potential distribution areas of the species in the coming years will gradually decrease, and in the SSP5 8.5 model, which represents the highest level of world resource usage this gradual decrease will reach its highest level and there will be no suitable distribution area left for the species. Therefore, it is predicted that the species will become endangered. In-situ and ex-situ conservation measures need to be taken to ensure the sustainability of the species in forestry and landscape areas.

Holocene vegetation and flora dynamics of the west Cork/Kerry region, south-western Ireland

AbstractSediments from a small lake, Loch Beag, in Barrees, Beara peninsula, south-western Ireland, provide a record of vegetation history that spans most of the Lateglacial and Holocene (14–0.43 ka). The detailed part of the record relates to the Holocene, which is the focus of this paper. The investigations carried out include pollen and macrofossil analyses, loss-on-ignition measurements and 14C dating. As well as providing records for tree and shrub taxa, and especially Pinus, Quercus, Ulmus, Fraxinus and Taxus, other taxa mainly with Atlantic and/or Lusitanian distributions are also considered. These include Arbutus unedo (strawberry tree) and fern species such as Osmunda regalis, and the filmy ferns Hymenophyllum tunbrigense, H. wilsonii and Trichomanes speciosum (Killarney fern). Detailed records for a suite of bog/heath taxa, including ericoid species (Erica tetralix and E. cinerea), Narthecium ossifragum, Hypericum elodes and Myrica gale, are presented. The results of 14C dating of bog-pines from western Ireland are summarised. Results of other investigations, including key Holocene pollen diagrams, and charcoal and fossil-wood records from archaeological excavations that relate mainly to the Bronze Age in the wider west Cork/Kerry region, are reviewed. Vegetation dynamics, human impact and plant biogeography are discussed in the light of the considerable data now available for the region.

Antityrosinase activity and LC-MS/MS analysis of optimized ultrasound-assisted condition extracts and fractions from strawberry tree (Arbutus unedo L.).

Investigation of utilization possibilities of natural sources has been an important area for research. Tyrosinase inhibitory activity plays a key role in food and medicine industry. Strawberry tree (Arbutus unedo), a widely distributed plant among Mediterranean countries, possess fruits and leaves with rich bioactive phytochemicals, especially polyphenolic compounds. In this study, we aimed to investigate the antityrosinase activity of the fruit and leaf extracts of the plant, and to determine the phenolic compounds that contribute to the antityrosinase activity. In this regard, we evaluated the effect of solvent composition on the extraction of phenolic compounds from A. unedo and on its antityrosinase activity using a simplex centroid design approach, and used chromatographic and LC-MS/MS techniques. The leaf extracts prepared using EtOH:water (50:50) provided higher TPC (456.39 mg GAE/g extract) and acetone:EtOH:water (33:33:33) provided higher TFC (56.15 mg QE/g extract) values than of fruit extracts. LC-MS/MS analysis revealed 23 phenolic/flavonoid compounds in leaf extracts (L1-8), and major metabolites were detected as quercitrin, quinic acid, catechin, tannic acid, isoquercitrin, gallic acid, and ellagic acid. Among the leaf extracts, L3 (aceton:water, 50:50) exhibited 72.01% tyrosinase inhibition at 500 μg/mL. After fractionation studies guided by antityrosinase activity, its subfraction L3-Fr2 exhibited 40.06% inhibition at 50 μg/mL concentration (IC50: 146 ± 7.75 μg/mL), and catechin (113.19 mg/g), tannic acid (53.14 mg/g), ellagic acid (22.14 mg/g), gallic acid (10.27 mg/g), and epicatechin gallate (8.65 mg/g) were determined as major metabolites. Its subfraction L3-Fr2-sub7 exhibited better antityrosinase activity (IC50: 206.23 ± 9.87 μg/mL), and quantitative analysis results revealed the presence of tannic acid (127.40 mg/g), gallic acid (13.96 mg/g), ellagic acid (7.66 mg/g), quercetin-3-O-glucuronide (5.06 mg/g), and quinic acid (3.2 mg/g) as major metabolites, and correlation analysis showed that ellagic acid and quinic acid were positively correlated with antityrosinase activity.

Plant diversity in old-growth woods: the case of the forest edges of the Favorita Park in Palermo (north-western Sicily, Italy)

This article presents the results of a study on plant diversity at different levels in residual forest stands, located in the historical Favorita Park in Palermo, Italy (established and named in 1799 by King Ferdinand IV of the House of Bourbon). These forest aspects have naturally evolved for over two centuries, under minimal conditions of anthropogenic disturbance (e.g. deforestation, fires, grazing activities, etc.). This is especially true in the area known as “Bosco Niscemi”, spread over about 8.5 hectares, in the centre of the park. Bosco Niscemi is characterized by the widespread presence of old trees, abundant necromass and litter. In this study, four different soil profiles were analysed, and classified as follows: (i) Solimovic Regosol (Arenic); ii) Eutric Arenosol (Chromic); (iii) and (iv) Skeletic Regosol (Ochric). From a phytosociological point of view, four forest communities have been identified, two of which are described as new associations (Viburno tini-Phillyreetum latifoliae ass. nova and Teucrio flavi-Phillyreetum latifoliae ass. nova). The species richness was also found to be noteworthy, with the co-occurrence of several taxa (phanerogams and cryptogams) that are of biogeographic interest or rare in Sicily, including: i) vascular flora (e.g. Viburnum tinus and Arbutus unedo, both very rare throughout the western sector of Sicily); ii) bryophytes [Cryphaea heteromalla (new record of a very rare species in Sicily) as well as Hypnum cupressiforme and Leptodon smithii, also never previously found at such low altitudes]; iii) lichens (e.g. Bacidia rosella, Gyalecta derivata, Ramalina roesleri and Waynea stoechadiana); iv) mushrooms (e.g. Eichleriella leucophaea, only known location in Italy). Based on the scientific documentation produced in this study, these woods can be reported as “old-growth forests” to be included in the “National Network” that has been recently established in Italy (Ministerial Decree of 23 June 2023). This area might serve as an ideal control for urban environmental studies, given its pristine ecological setting.

The Application of Probiotic Bacteria from Strawberry (Fragaria ananassa × Duch.) in the Fermentation of Strawberry Tree Fruit (Arbutus unedo L.) Extract.

The search for unexplored plant resources that would provide a good basis for the development of novel probiotic functional foods is rapidly increasing. In this context, the strawberry tree fruit (Arbutus unedo L.) is particularly interesting, as it is rich in numerous antioxidant bioactive compounds that have been shown to be beneficial to health, but have not yet found industrial applications. In this work, the probiotic characterization of lactic acid bacteria strain Lactiplantibacillus plantarum DB2, isolated from strawberries (Fragaria ananassa × Duch.), was performed. The tested strain proved to be safe to use, displaying no antibiotic resistance or hemolytic activity. Due to its proven probiotic potential during simulated gastrointestinal transit, its antimicrobial activity, and its coaggregation with pathogens, it was selected for fermentation of an aqueous Arbutus unedo L. extract, which was subsequently microencapsulated and freeze-dried to extend its shelf life and preserve its functional properties. The antioxidant activity of the ferment obtained was maintained (80%), while after microencapsulation and freeze-drying, about 50% and 20% of the antioxidant activity was retained, respectively. In conclusion, this study demonstrates for the first time the application of probiotics isolated from strawberries in the fermentation of strawberry tree extract and monitors the antioxidant activity during post-fermentation formulation, paving the way for a potential industrial application of this underutilized plant.

Changes in Quality Characteristics of Strawberry Tree (Arbutus unedo L.) Fruit Packed with Perforated Polyethylene Terephthalate During Cold Storage

Changes in Quality Characteristics of Strawberry Tree (Arbutus unedo L.) Fruit Packed with Perforated Polyethylene Terephthalate During Cold Storage

Characterisation of Low Molecular Weight Compounds of Strawberry Tree (Arbutus unedo L.) Fruit Spirit Aged with Oak Wood

There is a trend towards the commercialisation of strawberry tree fruit spirit (AUS) with wood ageing, motivated by its favourable sensory characteristics. Additionally, further studies are necessary to elucidate the optimal conditions regarding ageing time and toasting level. This study evaluated the changes in colour and low molecular weight compounds (LMWC) of AUS aged for three and six months using oak wood (Quercus robur L.) with light, medium and medium plus toasting levels. For this purpose, phenolic acids (gallic, ellagic, ferulic and syringic acids), phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and furanic aldehydes (furfural, 5-hydroxymethylfurfural and 5-methylfurfural) were quantified using the HPLC method. Chromatic characteristics, colour sensory analysis and total polyphenol index were also analysed. Fourier transform near-infrared spectroscopy (FT-NIR) was used to discriminate between samples. The results emphasized the favourable effect of oak wood contact on enhancing the colour and enriching AUS with low molecular weight compounds (LMWC). AUS aged in medium toasted wood exhibits high levels of total phenolic index, 5-hydroxymethylfurfural, furfural, coniferaldehyde, sinapaldehyde, sum LMWC and chromatic characteristics b* and C. Concentrations of syringaldehyde, ellagic acid, vanillin and syringic acid and a lighter colour (a* chromaticity coordinates) are higher in AUS aged with slightly more toasted wood. Nearly all analysed parameters showed an increase with ageing time. The FT-NIR technique allowed for the differentiation of aged AUS, focusing more on ageing time than on toasting level.

Elemental and Radiological Characterisation of Arbutus unedo L. Leaves and Tea: Impact of Preparation Method on Nutritional Risk/Benefit.

The aim of this study was to characterise the elemental and radiological composition of strawberry tree (Arbutus unedo L.) leaves and tea preparations and compare it with commercial Uvin H herbal mixture, widely used in treatment of urinary tract infections. The concentration of 17 elements and the activity concentration of selected radionuclides were measured in strawberry tree leaves/Uvin H herbal mixture, as well as in herbal tea prepared by infusion or decoction of leaves for 5 or 10 min. In both leaves and tea preparations, Ca, K, Mg, and Na were the most abundant elements, while the lowest levels were measured for As, Co, Mo, and Se. Only 137Cs and 40K were detected in analysed leaves/herbal mixture, while the activity of radionuclides in tea preparations was below the detection limit. The maximum possible health benefits can be obtained by a 10-min decoction of leaves, which resulted in the highest total phenolic content and antioxidant activity and levels of K, Ca, Mg, Na, Fe, Mn, and Se in comparison to the other preparation methods evaluated in this study. The calculated intake of potentially toxic elements and radionuclides does not represent a health risk to consumers.

Wild ungulate effects on soil fungal diversity in Mediterranean mixed forests

The effect of wild ungulate density on ecosystems varies according to different factors: climate and physiography conditions, forest type, management history, and herbivore identity. In this study, we evaluated the effect of historically high densities of red deer (Cervus elaphus L.) on the soil fungal communities in Mediterranean ecosystems using 30 paired plots, open on the one hand and exclosure plots on the other one. Plots were established at the end of 2020 in a perimeter-fenced hunting estate of 6600 ha in Toledo, Spain. Three months after plots were established, we analysed fungal communities in 60 soil samples using Illumina 250-bp paired-end sequencing. We estimated changes in total fungal richness and in the richness of trophic groups through Linear Mixed Effects models using fenced/unfenced type and deer habitat use as fixed variables and the location of the plots and the main tree host species as random variables. Fungal composition was analysed using non-metric multidimensional scaling and permutational multivariate ANOVA; edaphic characteristics were incorporated to explain differences. Soil fungal communities were not differentially affected by excluding ungulates for three months. Areas with high deer densities had a richer saprotrophic community and where lowland environments were dominated by the main tree hosts Quercus faginea and Quercus ilex. Arbutus unedo was found in mountain areas where there was less herbivore pressure, a greater richness of ectomycorrhizal and lichenized fungi and soils positively associated to nitrogen, phosphorus, potassium and organic matter levels.

Spectral Library of Plant Species from Montesinho Natural Park in Portugal

In this work, we present and describe a spectral library (SL) with 15 vascular plant species from Montesinho Natural Park (MNP), a protected area in Northeast Portugal. We selected species from the vascular plants that are characteristic of the habitats in the MNP, based on their prevalence, and also included one invasive species: Alnus glutinosa (L.) Gaertn, Castanea sativa Mill., Cistus ladanifer L., Crataegus monogyna Jacq., Frangula alnus Mill., Fraxinus angustifolia Vahl, Quercus pyrenaica Willd., Quercus rotundifolia Lam., Trifolium repens L., Arbutus unedo L., Dactylis glomerata L., Genista falcata Brot., Cytisus multiflorus (L’Hér.) Sweet, Erica arborea L., and Acacia dealbata Link. We collected spectra (300–2500 nm) from five records per leaf and leaf side, which resulted in 538 spectra compiled in the SL. Additionally, we computed five vegetation indices from spectral data and analysed them to highlight specific characteristics and differences among the sampled species. We detail the data repository information and its organisation for a better understanding of the data and to facilitate its use. The SL structure can add valuable information about the selected plant species in MNP, contributing to conservation purposes. This plant species SL is publicly available in Zenodo platform.

Food Authentication: The Detection of Arbutus unedo and Olea europaea Leaves as an Admixture of Oregano Using LAMP- and Duplex LAMP-Based Test Systems with Lateral-Flow Assays

The Mediterranean herb oregano is one of the most frequently adulterated foods. Often morphologically similar leaf material is used as a filler, which can generally be detected using DNA-based methods. Loop-mediated isothermal amplification (LAMP) has high potential for point-of-care testing as it requires only a simple device for sample incubation and is less sensitive to inhibition by co-isolated metabolites compared to conventional PCRs (polymerase chain reactions). In this work, we have developed two LAMP assays for the specific detection of the adulterants olive (Olea europaea) and strawberry tree (Arbutus unedo). The combination with a rapid isolation protocol and LFAs (Lateral-flow assays) as a visualization technique provides a reliable indication of possible adulteration. It has also been shown that it is possible to estimate the level of contamination and to perform the LAMP/LFA assay with DNA isolation in less than 30 min. As a further option, a duplex LAMP/LFA assay was developed that allows both contaminants to be detected in parallel, making the rapid test system even more cost-effective and user-friendly.

Biscogniauxia rosacearum: A newly identified pathogen of strawberry tree (Arbutus unedo L.) in North Africa

AbstractBiscogniauxia species are opportunistic pathogens primarily associated with Quercus species dieback in the Mediterranean basin. Among these species, Biscogniauxia mediterranea stands out as the only species previously documented in Tunisia, affecting Quercus suber and Erica multiflora. This study unveils a novel finding, reporting the presence of Biscogniauxia rosacearum on Strawberry trees in Tunisia. The identification of B. rosacearum isolates was confirmed based on DNA sequence data (ITS, TUB2 and ACT) and morphological traits. Artificial inoculation trials on leaves confirmed the pathogenicity of the fungus towards Arbutus unedo. This finding emphasizes the significance of implementing proactive measures to effectively combat this pathogen because of the polyphagous nature of Biscogniauxia species that raises concerns about its potential spread within vulnerable hosts in Tunisian oak forests.

Acidic soil-tolerant tree species identification

Previously, surface soil acidity was amended by the application of lime, gypsum, and acidic soil-tolerant crop species. However, their effectiveness in subsurface soil acidity reduction is limited. Thus, this review paper aimed to screen the tree species that easily overcome such problems. Scopus, Science Direct, Google Scholar, African journals online, and Google search engine databases were used. A total of 60 acidic soil-tolerant tree species were identified. Acacia auriculiformis, Acacia crassicarpa, Arbutus unedo L., Casuarina junghuhniana, and Erythrina abyssinica were among the extremely acidic soil-tolerant tree species. Whereas Acacia cincinnata, Acacia mangium, Pinus patula, Albizia saman, Citrus x paradisi, and Cassia reticulata were belongs to some of the strong acidic soil tolerant tree species. Generally, the species' acidic tolerance capacity and planting site compatibility should be considered for the success of amendment works. Scaling out these species and large-scale plantations should be done in addition to estimating their relative percent of acidic soil amendment roles. Producing stable food in line with reclaiming acidic soil is achieved through the integration of stress tolerant fruit trees. Research on large-scale plantations, domestication, skilling up and comparative evaluation of their levels of acidic soil amendment capacity should be performed in the future.

Fruit Quality and Biochemical Characteristics of Different Strawberry Tree (Arbutus unedo L.) Genotypes Grown In Giresun

Fruit quality, chemical and biochemical properties of strawberry tree (Arbutus unedo L.) genotypes that naturally spread in Bulancak district of Giresun province were examined. In this context, as a result of examinations carried out on 20 genotypes subject to research were determined fruit weight 2.39-4.69 g, fruit width 16.85-20.62 mm, fruit length 14.52-17.29 mm, pH 3.36-3.88, SSC 11.60-19.60%. Glucose, sucrose, fructose and total sugars of water soluble sugars in arbutus genotypes were analyzed and respectively 2.32-8.34 g 100 g-1, 0.02-1.93 g 100 g-1, 3.08-17.93 g 100 g-1 and 7.47-27.51 g 100 g-1 values were obtained. The amount of vitamin C contained in the fruits of strawberry tree was determined as 13.53-126.60 mg 100 g-1, the amount of citric acid was 0.16-0.69% and the amount of malic acid was 0.27- 1.30%.