Search Results (7)

Coastal Pyrus spinosa seedlings were tested for their developmental, chlorophyll content and antioxidant performance under soil saline conditions where bacterial and l-methionine exogenous treatments were applied as potential saline alleviation stress schemes. Scaling up saline stress, the number of formed lateral shoots was reduced in all treatments. Medium salt stress (75 mM NaCl) demonstrated a rather unified decline in shoot fresh weight values, which became toxic at 100 mM NaCl, with up to 89.1% shoot fresh weight losses, in comparison to unchallenged status. Both exogenous applications increased root/shoot ratio, providing developmental boost for root growth. Total chlorophyll content values (May–July) did not differ among non-stressed plantlets independently of exogenous treatment. All experimental plantlet lines increased their antioxidant activity on scaled up soil NaCl enrichment. Νo differences in root orientation and their angle frequencies were observed while soil saline exposure took place. In brief, spring–summer exposure of P. spinosa plantlets under 100 mM NaCl saline stress can be manageable, achieving higher root/shoot ratio values, upregulating leaf antioxidant activity and optimizing root growth upon bacterial and l-methionine supplementation. However, many of the examined parameters were found to be not extensively different between exogenously treated plantlets and non-supplemented ones, suggesting a potential role of intergenerational and transgenerational stress memory. Full article

Pyrus spinosa (PS), also known as wild pear, is an indigenous species to the Mediterranean basin. It has attracted interest for its potential use in the food and beverage industries due to its antioxidant properties. This research aims to develop an antioxidant-rich PS fruit extract by optimizing the extraction parameters. More specifically, through a comprehensive study of the extraction parameters (including extraction duration, temperature, and ethanol concentration), the optimal conditions were determined that can achieve the highest antioxidant properties. High-Performance Liquid Chromatography (HPLC) was employed for the identification and quantitation of the polyphenolic compounds present in PS fruits. The optimized extraction conditions significantly enhanced the antioxidant properties of the extract, with the total polyphenol content increasing by up to 345% (reaching a value of 50.97 mg gallic acid equivalents per g of dry weight in the optimum sample), total flavonoid content by up to 273%, and ascorbic acid content by up to 653%. Furthermore, the antioxidant capacity of the extracts increased by 2356% (by FRAP method) and 1622% (by the DPPH method), with varying extraction parameters. These findings highlight the importance and the effectiveness of optimizing the extraction parameters in order to increase the antioxidant properties of PS fruit extract. Based on these findings, PS extracts can be further utilized in the food and beverage industries to develop new products that will benefit from the antioxidant properties. Full article

The genus Pyrus has a long history in Sardinia (Italy), where two wild pear species (P. spinosa Forssk. and P. pyraster (L.) Burgsd.) and Pyrus communis L. cultivars are extensively distributed. Even if neglected, these taxa represent well-adapted key resources for redesigning sustainable farming systems. This report aims at shedding light on the phenolic fingerprint and antioxidant properties of wild pear fruits and comparing their traits with those of the studied pear cultivar germplasm (PCG). Fruits of wild pear species were collected, and flesh, peel, and core subsamples were analyzed. Moreover, available data from previous research on PCG were analyzed. The contents of total phenolics (TotP), total flavonoids (TotF), and condensed tannins (CT), as well as the antioxidant capacity, were similar in the flesh of the two wild species. However, P. spinosa had significantly higher values of TotP (89 g GAE kg⁻¹ DM) and CT (33 g DE kg⁻¹ DM) in the peel. Eleven individual phenolic compounds were identified and quantified in the fruit flesh, 14 in both peel and core. For both wild species, arbutin and chlorogenic acid were the main phenolic compounds, followed by the quercetin glycosides. Comparing the antioxidant capacity and TotF fruit flesh values of wild pears with those of PCG, the latter resulted up to 15-fold lower. The wild types showed unique metabolite profiles. Results support novel insights on the phytochemicals of wild pear fruits. Full article

A large portion of the Mediterranean basin suffers from a lack of organic carbon in the soil and low woody cover percentages, resulting in a very high risk of desertification. In such conditions, knowing the effects on below and above ground carbon sequestration of pioneer woody species is of great importance, although barely assessed at the individual level. In this study, we first investigated whether almond-leaved pear (Pyrus spinosa) individuals influence soil organic carbon (SOC) concentration and stock in comparison with surrounding pasturelands inside a natural reserve in Sicily, Italy. Second, we evaluated inter individual variability on such storage, testing the effects of plant height, basal diameter, canopy cover and tree structure (single or multiple stems). Soils under pear presented, on average, a significantly higher SOC than pasturelands (3.86% and 3.16%, respectively) as well as a lower bulk density (1.09 and 1.28 g cm⁻³, respectively). Due to a lower soil compaction, SOC stocks (130.3 and 113.9 Mg ha⁻¹, respectively) did not differ significantly. Below and aboveground biomass carbon accounted for a small fraction of carbon stock, while neither pear structure, age nor tree structure significantly influenced SOC concentration and SOC stock. Despite the need of further investigations, our results indicate that pear may represent an excellent tree species to improve carbon storage, both while triggering the restoration of Mediterranean woodlands or increasing biodiversity in pasturelands and agroforestry systems, that, indeed, can hold high SOC if well managed. Full article

Pyrus spinosa Forssk. (almond-leaved pear) is a wild-growing native tree of the hilly countryside of Greece, which has recently gained interest for its valuable endogenous substances. In the present work, the determination of the total phenol content (TPC) and antioxidant capacity (AC) was carried out during 2021 and 2022 in leaves from 32 genotypes of mature wild-growing trees at four different locations of Central Macedonia District, Greece: Agia Anastasia, Chalkidiki, Lagadas and Pieria. The measurements taken from the leaf samples of all genotypes revealed a strong positive linear correlation between TPC and AC (R² = 0.772). Two genotypes from Agia Anastasia, coded as AA2 and AA3, were comparatively the richest in TPC (44.86 for AA2 and 46.32 mg GAE/g fresh weight for AA3) and AC (70.31 and 71.21 μg AAE/g fresh weight for the same genotypes). For these two genotypes of high TPC and AC, an efficient micropropagation protocol was developed to preserve and multiply this valuable germplasm. Newly emerged shoot tips were excised from winter shoots and, after disinfestation, they were established on a modified Murashige and Skoog (MS) nutrient medium with 5 μΜ of 6-Benzyloaminopurine (BAP). For shoot multiplication, explants from clean cultures were transferred to Pear Medium 1 with 5 μΜ of BAP. The effect of the nutrient medium was tested by using five different nutrient media (modified MS, Pear Medium 1, Pear Medium 2, DKW and WPM) supplemented with 5 μΜ of BAP. Pear Medium 1 was the most effective in shoot formation. Among the four different BAP concentrations (0, 5, 10 and 20 μΜ) used in Pear Medium 1, 5 μΜ of BAP resulted in the production of the significantly highest number of shoots (22.7 shoots per explant, 2.4 cm long). The exposure of cultures to 10 μmol·m⁻²·s⁻¹ for one week under light irradiance followed by 35 μmol·m⁻²·s⁻¹ for four weeks increased both the number and length of the shoots produced. A 20-s dip of the shoot bases into 49.0 μΜ of Indole-3-butyric acid (IBA) in EtOH equally affected rooting in a modified rooting MS (79%) and Pear Medium 1 (80%). The root system developed better in the modified rooting MS medium (mean number of roots of 2.7 with a length of 3.9 cm). The acclimatization of the plantlets was successfully carried out (high survival rates five weeks after their establishment) on a perlite substrate under controlled environmental conditions. Full article

Urban streams are ecosystems of great ecological and hydrological importance for human environments. However, they face pressure on biodiversity, hydromorphology, and water quality. In this study, an urban riparian system of a Mediterranean city (Thessaloniki, Greece) which interacts with several land-use classes, namely forests, pastures, cultivations, industrial-commercial infrastructure, and light and dense urban fabric, is assessed. The analyzed data were collected by implementing mainly QBR and ancillary RMP protocols on 37 plots of the Dendropotamos stream. The QBR protocol provided an assessment of total riparian vegetation cover, cover structure and quality, as well as channel alterations. The RMP protocol was used to enhance the quantitative assessment of dominant tree and shrub cover. Parts of Dendropotamos surrounded by agricultural (median QBR score: 27.5), industrial (50), and dense residential areas (27.5) suffer, in general, from low riparian vegetation cover, bad vegetation structure and quality, the continuous presence of alien/introduced species, and channel alterations. A variety of riparian habitat conditions characterize the sparse residential areas (60) where cover structure and quality of vegetation is improved. The reduction in grazing pressure has improved the riparian habitat in the greatest part of Dendropotamos that is surrounded by semi-natural pastures (65). Within forested areas (85), the stream conditions are considered quasi-natural. All previous land uses are differentiated in terms of the dominant trees found in the vegetation of Dendropotamos: Platanus orientalis in forested areas, alien Ailanthus altissima mainly in residential and industrial areas, and native shrubs, e.g., Quercus coccifera and Pyrus spinosa, in pastures. The QBR protocol could be a valuable tool in urban environment planning to help identify areas with potential for restoration, such as those with moderate residential pressure. Full article

Almond-leaved pear (Pyrus spinosa Forssk., Rosaceae) is a scientifically poorly researched and often overlooked Mediterranean species. It is an insect-pollinated and animal-dispersed spiny, deciduous shrub or a small tree, with high-quality wood and edible fruits. The aim of the study was to assess the phenotypic diversity of almond-leaved pear in the eastern Adriatic region. The examination of phenotypic diversity was based on a morphometric analysis of 17 populations using ten phenotypic traits of leaves. Varieties of multivariate statistical analyses were conducted to evaluate the within- and among-population diversity. In addition, the Mantel tests were used to test the correlations between geographic, environmental, and phenotypic differences among populations. High phenotypic variability was determined both among and within the studied populations. Leaf-size-related traits proved to be the most variable ones, in contrast to more uniform leaf shape traits. Furthermore, three groups of populations were detected using multivariate statistical analyses. The first group included trees from northern- and southernmost populations characterized by high annual precipitation. However, the trees from the second and third group were highly overlapped without a clear geographical pattern. In addition, we revealed that both environmental and geographical interactions proved to be responsible for the patterns of phenotypic variation between almond-leaved pear populations, indicating significant isolation by environment (IBE) and isolation by distance (IBD) patterns. Overall, our results provide useful information about phenotypic diversity of almond-leaved pear populations for further conservation, breeding, and afforestation programs. Full article