Search Results (14)

The European ground squirrel (Spermophilus citellus) is an endangered mammal that inhabits open habitats with low vegetation in central and southeastern Europe. Its southernmost range includes northern Greece, where populations are declining due to habitat degradation and fragmentation. Limited behavioural research on Greek populations underscores the need for studies to support conservation efforts. The present study examined the species’ diet and seasonal changes in food consumption in an anthropogenic area of Central Macedonia, Greece. Between 2022 and 2023, feeding behaviour was documented recording plant parts, taxa, and feeding durations, while plant availability was assessed through surface sampling. The results revealed that Cynodon, Carex–Cyperus, Salvia, Solanum, and Plantago were the dominant plant genera in the species’ diet, while rhizomes and leaves were the most frequently consumed plant parts. Seasonal dietary shifts were observed, with ground squirrels selecting specific plants and plant parts based on availability. Under resource-limited conditions, they adapted by consuming nutritious rhizomes or the less-common, but toxic, S. elaeagnifolium. These findings highlight the species’ dietary adaptability to Mediterranean and human-modified environments, providing valuable ecological insights and informing habitat conservation and improvement strategies. Full article

The grafting technique has successfully mitigated crop losses from diseases and stress in vegetable production; however, vegetable grafting in Tanzania is very limited. Field and greenhouse experiments conducted in Tanzania’s mainland and islands compared the response of tomato determinate cv. ‘Tanya’ to production challenges when ungrafted and grafted onto five tomato rootstocks (‘Hawaii 7796’, ‘Tengeru 1997’, ‘Tengeru 2010’, ‘R3034’, and ‘Shelter’), one eggplant variety (‘EG 203’), and one wild Solanum species (Solanum elaeagnifolium). The visual symptoms of bacterial wilt varied significantly with location and season, ranging from 8 to 100%, attributed to varying bacterial wilt pressures and strains of Ralstonia solanacearum isolated (Phylotype I sequevars 17, 18, and 31). ‘EG203’ and ‘Hawaii 7796’ emerged as the most effective rootstocks, reducing wilting by 49.8 and 51.0% and improving yield by 57.2% and 27.7% on average across experiments conducted in three locations (Moshi, Pemba, and Unguja) over two seasons. Combining reduced water supply with grafting resulted in an average reduction in wilting of 76%, while also boosting yields by an average of 3.6 times in experiments conducted in Arusha over two seasons. Grafting onto ‘Hawaii 7796’ and ‘Shelter’ significantly improved ‘Tanya’ yields by 38.3% and 41.6% on average over two seasons, only under standard nutrient application rates. While certain rootstocks improved crop performance, yields across various sites and seasons were significantly hampered by pest pressure. These findings support grafting’s potential to mitigate damage from common stresses, emphasizing the need for further research to identify suitable rootstocks for optimizing returns on investments in grafted plants in Tanzania. Full article

In the present investigation, the phenolic compounds of Solanum elaeagnifolium were identified, and the plant’s anti-lipase and anti-glycation effects on hemoglobin were discovered through in vitro experiments, as well as its short-term antihyperglycemic and anti-inflammatory effects. The chemical compound composition was detected using HPLC-DAD, the anti-lipase activity was tested in vitro using 4-nitrophenyl butyrate as a substrate, and the antiglycation activity of the plant extracts was also tested in vitro using a haemoglobin model. The antihyperglycemic effect was determined by inhibiting pancreatic α-amylase and α-glycosidase activity and performing an in vivo glucose tolerance test on normal rats, and the anti-inflammatory activity was determined by inducing paw inflammation with carrageenan. In both the SEFR (fruit) and SEFE (leaf) extracts, chromatographic analysis revealed the presence of quercetin 3-O-β-D-glucoside, rutin, and quercetin. SEFR inhibited the pancreatic lipase enzyme more effectively, with an IC₅₀ of 0.106 ± 0.00 mg/mL. S. elaeagnifolium extracts demonstrated significant antiglycation activity, with 3.990 ± 0.23 mg/mL of SEFE and 3.997 ± 0.14 mg/mL of SEFR. When compared to positive and negative controls, plant extracts had very significant anti-diabetic and anti-inflammatory effects. The findings in this study and previous research on this plant encourage us to investigate other pharmacological activities of this plant besides its duiretic, cictrisant, and anti-ulcer activity. Full article

We aimed to explore how the invasion of the alien plant Solanum elaeagnifolium affects soil microbial and nematode communities in Mediterranean pines (Pinus brutia) and maquis (Quercus coccifera). In each habitat, we studied soil communities from the undisturbed core of both formations and from their disturbed peripheral areas that were either invaded or not by S. elaeagnifolium. Most studied variables were affected by habitat type, while the effect of S. elaeagnifolium was different in each habitat. Compared to maquis, the soil in pines had higher silt content and lower sand content and higher water content and organic content, supporting a much larger microbial biomass (PLFA) and an abundance of microbivorous nematodes. The invasion of S. elaeagnifolium in pines had a negative effect on organic content and microbial biomass, which was reflected in most bacterivorous and fungivorous nematode genera. Herbivores were not affected. In contrast, in maquis, organic content and microbial biomass responded positively to invasion, raising the few genera of enrichment opportunists and the Enrichment Index. Most microbivores were not affected, while herbivores, mostly Paratylenchus, increased. The plants colonizing the peripheral areas in maquis probably offered a qualitative food source to microbes and root herbivores, which in pines was not sufficient to affect the much larger microbial biomass. Full article

In this study, the chemical composition and the antioxidant and antidiabetic properties of S. elaeagnifolium flower (SEFl), fruit (SEFr), and leaf (SEFe) extracts were investigated in vitro and in silico. HPLC-DAD analysis was used to determine the chemical components. Colorimetric techniques were used to identify polyphenols and flavonoids. The antioxidant capacity was determined using DPPH and TAC assays. The antidiabetic activity was examined using the enzymes α-amylase and α-glucosidase. Molecular docking methods were used to assess the anti-dipeptidyl peptidase IV (DPP-IV) activity. According to HPLC findings, extracts of S. elaeagnifolium flowers, leaves, and fruits are rich in salicylic acid, sinapic acid, chlorogenic acid, naringin, quercetin, quercetin-3-O-beta-glucoside, kaempferol, and chalcone. The IC₅₀ for flower, leaf, and fruit extracts were 132 ± 5.59 μg/mL, 43.19 ± 1.46 μg/mL, and 132 ± 5.59 μg/mL, respectively. The total antioxidant capacity of SEFr, SEFe, and SEFl were determined to be 900.06 ± 4.01 μg AAE/mg, 792.10 ± 6.72 μg AAE/mg, and 681.10 ± 3.02 μg AAE/mg, respectively. Importantly, SEFe, SEFl, and SEFr displayed significant anti-α-amylase activity, with IC₅₀ values of 79.16 ± 2.35 µg/mL, 99.16 ± 1.17 µg/mL, and 40.31 ± 2.04 µg/mL, respectively. The results also showed that SEFr, SEFe, and SEFl all exhibited potent anti-α-glucosidase activity, whose IC₅₀ values were determined to be 20.53 ± 0.37 µg/mL (SEFr), 20.05 ± 0.12 µg/mL (SEFe), and 41.1 ± 1.55 µg/mL (SEFl). Molecular docking of S. elaeagnifolium phenolic compounds in the active site of DPP-IV revealed a strong inhibitory effect, with a glide score ranging from −2.63 to −8.10 Kcal/mol. Notably—with glide scores of −8.10, −6.23, −5.73, and −5.37 Kcal/mol—rutin, quercetin-3-O-beta-glucoside, chalcone, and naringin were the most active molecules against DPP-IV. Full article

Invasive alien plants have severe impacts on biodiversity and ecosystem services worldwide. To assess the invasion of Solanum elaeagnifolium Cav. (a major alien invasive plant; Solanaceae) in Greek protected areas (PAs), we conducted an extensive drive-by survey across the country crossing half of the Greek Natura 2000 sites. The occurrence data were then linked in GIS with (i) the boundaries of the Natura 2000 sites, (ii) the mapped habitat types in the invaded sites, and (iii) the Corine land cover, from which we calculated the ecosystem services. The results showed that approximately 24% of the investigated PAs were invaded by S.elaeagnifolium to varying degrees of extension and density of the populations. A variety of 29 different habitat types of Annex I of the Directive 92/43/EEC (including a priority habitat and seven habitat types of national importance) were found to be invaded (one in four habitat types present in Greece). In the invaded Natura 2000 sites, we recorded human activities/threats that were mostly related to agricultural activities of high intensity, while the potential in ecosystem service provision was relatively low for the category of regulating services in the invaded sites. Our study provides the first nationwide report of the distribution of S. elaeagnifolium in Natura 2000 sites of Greece, providing baseline maps and information for future monitoring. Our results highlight the need of an effective management strategy across the Natura 2000 network to effectively protect the local biodiversity, which should include management measures for invasive species, mitigating habitat fragmentation, and soil degradation, as well as the adaptation of eco-enhancing management strategies for the provision of multiple ecosystem services in agriculture. Full article

The increased demand for the adoption of sustainable practices to protect agroecosystems is challenged by the introduction and dominance of invasive plant species (IPS). The management of IPS requires a direct response from farmers and policy makers and is often associated with the adoption of practices that have negative ecological impacts. Solanum elaeagnifolium Cav. (silverleaf nightshade) is a noxious IPS posing a serious threat to agriculture and the environment. The increased resistance to the biotic and abiotic stress factors caused by high phenotypic plasticity, dense trichomes, and spines allow the weed to adapt to many habitats, rendering several herbicides ineffective. If an early detection and eradication fails, multiple management strategies should be adopted to mitigate a further dispersal. Herbicides should be applied before or during flowering to prevent the formation of berries and the production of seeds. Precision agriculture tools, such as decision support systems, can be exploited to reduce the herbicide input. Soil tillage should be avoided to prevent clonal reproduction. Mowing is an effective tool to prevent the setting of seeds. Biological agents should be carefully released as a part of an agroecological weed management framework. Future research should focus on the development of cross-boundary protocols and actions to monitor the introduction pathways for the early detection and agroecological management of S. elaeagnifolium. Full article

The present work was designed to study the chemical composition and the antioxidant and antimicrobial properties of fruits (SFr) and leaf (SF) extracts from Solanum elaeagnifolium var. obtusifolium (Dunal) Dunal (S. elaeagnifolium). The chemical composition was determined using HPLC-DAD analysis. Colorimetric methods were used to determine polyphenols and flavonoids. Antioxidant capacity was assessed with DPPH, TAC, and FRAP assays. Antimicrobial activity was assessed using disk diffusion and microdilution assays against two Gram (+) bacteria (Staphylococcus aureus ATCC-6633 and Bacillus subtilis DSM-6333) and two Gram (-) bacteria (Escherichia coli K-12 and Proteus mirabilis ATCC-29906), while the antifungal effect was tested vs. Candida albicans ATCC-1023. By use of in silico studies, the antioxidant and antimicrobial properties of the studied extracts were also investigated. HPLC analysis showed that both fruits and leaf extracts from S. elaeagnifolium were rich in luteolin, quercetin, gallic acid, and naringenin. Both SFr and SF generated good antioxidant activity, with IC₅₀ values of 35.15 ± 6.09 μg/mL and 132.46 ± 11.73 μg/mL, respectively. The EC₅₀ of SFr and SF was 35.15 ± 6.09 μg/mL and 132.46 ± 11.73 μg/mL, respectively. SFr and SF also showed a good total antioxidant capacity of 939.66 ± 5.01 μg AAE/and 890.1 ± 7.76 μg AAE/g, respectively. SFr had important antibacterial activity vs. all tested strains—most notably B. subtilis DSM-6333 and E. coli, with MICs values of 2.5 ± 0.00 mg/mL and 2.50 ± 0.00 mg/mL, respectively. SFr demonstrated potent antifungal activity against C. albicans, with an inhibition diameter of 9.00 ± 0.50 mm and an MIC of 0.31 ± 0.00 mg/mL. The in silico approach showed that all compounds detected in SFr and SF had high activity (between −5.368 and 8.416 kcal/mol) against the receptors studied, including NADPH oxidase, human acetylcholinesterase, and beta-ketoacyl-[acyl carrier protein] synthase. Full article

Solanum elaeagnifolium, one of the world’s most widespread invasive weeds, thrives in the regions of Tunisia with a semi-arid climate. An enhanced understanding of its biological traits could be useful for its management. For this purpose, S. elaeagnifolium vegetative propagation, flowering, fruiting, and spread patterns were assessed under semi-arid environmental conditions at Chott Mariem (Tunisia) over three years (2013–2015). Our results revealed that S. elaeagnifolium showed an active vegetative growth phase during the spring (March–May). Thereafter, the plant stopped its vegetative growth in June–August in favor of flowering and fruiting. The vegetative growth resumed during September–October and declined in November, announcing its dormant period. Thanks to its vigorous rhizomatous system, S. elaeagnifolium was able to emit offshoots within a radius of 1.5 m from parent shoots by 30 months after its establishment. These findings could inform and improve dedicated management control options for S. elaeagnifolium. Silverleaf nightshade should be controlled before the full-flowering stage in spring and following the first autumnal rainfall to prevent vegetative propagation and fruiting. Full article

To date, the effects of invasive plants on soil communities and the concomitant interactions thereof have been the subject of ever-growing concern. Solanum elaeagnifolium (S) is a noxious invasive weed originating from south-central America, which has been recognized as a serious threat around the Mediterranean basin and worldwide. Herein, we compared soil nematode communities in the rhizospheres of (S), against those of its native antagonist Cichorium intybus (C), in sites where these two ruderal plants coexist (“species” effect—hereafter “sp”). These sites differed regarding the time after the initial invasion of (S) and were regarded as recently and historically invaded (10 years and 70 years after invasion; “year” effect—hereafter “yr”). Neither “sp” nor “yr” affected total nematode abundance and nematode functional indices. Diversity was lower in (S) and was reduced even more with time after invasion in both plant species. Plant parasites decreased significantly from S–10yr to S–70yr, i.e., over time after invasion, while predators were fewer in (C). Distinct nematode communities in terms of genera structure were formed under the two plant species and these were significantly affected by the time after (S) invasion. Differences between these communities related to loss of genera but also to changes in the abundance of common ones, such as Acrobeloides and Pratylenchus. Our results showed that the responses of the examined soil communities to the invasion of (S) are not straightforward and cannot be easily explained on the basis of existing theories. However, the first-time results furnished herein may be useful to integrated management strategies in the future. Full article

Solanum elaeagnifolium is among the invasive plants of Morocco; studies on its chemical composition and biological activities are few in number in Morocco. S. elaeagnifolium has shown molluscicidal and nematicidal and cancer-inhibitory effects, anti-inflammatory, analgesic activity, and antibacterial activity. The objective of this research is to improve this plant and assess its antibacterial and antioxidant properties as well as its total polyphenolic content (TPC) and total flavonoid content (TFC). The Folin-Ciocalteu method and the aluminium-trichloride method were used to determine TPC and TFC in hydro-ethanolic (HEE) and hydro-acetonic (HAE) leaf extract. Three assays were performed to determine the antioxidant activity: the DPPH test (radical 2,2’-diphenyl-1-picrylhydrazyl), the FRAP test (Ferric Reducing Antioxidant Power), and the TAC test. Disk diffusion and microdilution were used to test antibacterial activity against four pathogenic bacteria and Candida albicans. The hydro-ethanolic extract 2.54 ± 0.4 mg EAG/g has a greater polyphenol concentration than the hydro-acetonic extract 1.58 ± 0.03 mg EAG/g. Although the flavonoid content of the hydro-acetonic extract (0.067 ± 0.001 mg EQ/g) is larger than that of the hydro-ethanolic extract (0.012 ± 0.001 mg EQ/g), the flavonoid content of the hydro-ethanolic extract (0.012 ± 0.001 mg EQ/g). The DPPH values were IC-50 = 0.081 ± 0.004 mg/mL for hydro-ethanoic extract and 0.198 ± 0.019 mg/mL for hydro-acetonic extract, both extracts superior to BHT (0.122 ± 0.021 g/mL). While the FRAP assay showed a low iron-reducing power values for both extracts compared to BHT), the overall antioxidant activity of the two extracts was found to be considerable. The overall antioxidant activity of the hydro-ethanolic extract was 8.95 ± 0.42 mg EAA/g, whereas the total antioxidant activity of the hydro-acetonic extract was 6.44 ± 0.61 mg EAA/g. In comparison with the antibiotic Erythromycin, HAE and HEE from S. elaeagnifolium leaves demonstrated significant antibacterial action. HAE had the best inhibitory efficacy against Bacillus subtilis DSM 6333, with an inhibition diameter of 10.5 ± 0.50 mm and a MIC of 7.5 ± 0.00 mg/mL, as well as against Proteus mirabilis ATCC 29906, with an inhibitory diameter of 8.25 ± 0.75 mm and a MIC of 15 ± 0.00 mg/mL. Full article

Buzz pollination is a specialized pollination syndrome that requires vibrational energy to extract concealed pollen grains from poricidal anthers. Although a large body of work has examined the ecology of buzz pollination, whether acoustic properties of buzz pollinators affect pollen extraction is less understood, especially in weeds and invasive species. We examined the pollination biology of Silverleaf nightshade (Solanum elaeagnifolium), a worldwide invasive weed, in its native range in the Lower Rio Grande Valley (LRGV) in south Texas. Over two years, we documented the floral visitors on S. elaeagnifolium, their acoustic parameters (buzzing amplitude, frequency, and duration of buzzing) and estimated the effects of the latter two factors on pollen extraction. We found five major bee genera: Exomalopsis, Halictus, Megachile, Bombus, and Xylocopa, as the most common floral visitors on S. elaeagnifolium in the LRGV. Bee genera varied in their duration of total buzzing time, duration of each visit, and mass. While we did not find any significant differences in buzzing frequency among different genera, an artificial pollen collection experiment using an electric toothbrush showed that the amount of pollen extracted is significantly affected by the duration of buzzing. We conclude that regardless of buzzing frequency, buzzing duration is the most critical factor in pollen removal in this species. Full article

Selection and breeding of eggplant (Solanum melongena) materials with good performance under low nitrogen (N) fertilization inputs is a major breeding objective to reduce environmental degradation, risks for human health, and production costs. Solanum elaeagnifolium, an eggplant wild relative, is a potential source of variation for introgression breeding in eggplant. We evaluated 24 plant, fruit, and composition traits in a set of genotyped advanced backcrosses (BC2 and BC3) of eggplant with S. elaeagnifolium introgressions under low N conditions. Significant differences were found between the two parents for most traits, and a wide phenotypic diversity was observed in the advanced backcrosses, with some individuals with a much higher yield, nitrogen use efficiency (NUE), and phenolics content than the S. melongena parent. In general, the lower the proportion of S. elaeagnifolium genome introgressed in the advanced backcrosses, the higher was the general phenotypic resemblance to S. melongena. Putative QTLs were detected for stem diameter (pd4), presence of prickles in stem (ps6), leaf (pl6) and fruit calyx (pc6), fruit width (fw7), chlorogenic acid content (cg5), total phenolic acid peaks area (ph6), chlorogenic acid peak area (ca1), and phenolic acids pattern (cp1). Our results reveal that introgression breeding of eggplant with S. elaeagnifolium has a great interest for eggplant breeding, particularly for adaptation to low N conditions. These materials can potentially contribute to the development of improved eggplant varieties for a more sustainable agriculture. Full article

Invasive alien plant species have impacts on nature conservation, ecosystem services and agricultural production. To identify environmental and human-related drivers of the invasion of Solanum elaeagnifolium (Solanaceae)—one of the worst alien invasive plants worldwide—we conducted an extensive drive-by survey across the Greek territory (presence/absence data; all national major multilane highways; 12–25% of the remaining road network; driven 3–5 times during 2000–2020). These data were linked in GIS with (i) physical environmental attributes (elevation, climate, soil properties) and (ii) type and intensity of human-related activities (land uses, settlements and road type). Compared to previous records, our survey showed that the range of S. elaeagnifolium increased by 1750% during the last decades, doubling its main distribution centers and reaching higher elevations. Our study revealed that the presence of S. elaeagnifolium is associated with (i) higher maximum temperatures and precipitation in summer and low precipitation in winter, as well as with (ii) soil disturbance related to agricultural activities, settlements and road networks, thus facilitating its spread mainly at low altitudes. Our study elucidates the current invasion pattern of S. elaeagnifolium and highlights the urgent need for its widespread monitoring, at least in the noninvaded areas in Greece that have been surveyed in this study. Preventative measures and integrative initiatives should be implemented quickly, and urgently incorporated into current agricultural, road network and conservation-management regimes. Full article