Olive Research Articles

Comparative analysis of cultivated and wild olive genotypes to salinity and drought stress.

The Mediterranean region's harsh conditions, characterized by low rainfall, high solar radiation, and elevated temperatures, pose challenges for vegetation, particularly in the face of climate change. Cultivated olive (Olea europaea subsp. europaea var. europaea) holds historical and economic significance as one of the oldest crops in the Mediterranean. Due to their high germplasm diversity and greater flowering abundance compared to the offspring of cultivated olives, wild olives (Olea europaea subsp. europaea var. sylvestris) could be utilized for selecting new olive cultivars capable of adapting to a changing climate. This research aimed to compare the effects of salt and drought stress on wild and cultivated genotypes by analyzing morphological, physiological, and biochemical parameters. Results showed that shoot length, shoot dry mass, and leaf area are key drought stress indicators in wild olive trees. The results indicated the olive trees more susceptible to salinity stress had lower Na+ and Cl- concentrations in their leaves and took longer to stabilize salt ion levels. Decreased K+ content in roots across all treatments indicated a general stress response. The uptake of Ca2+ appears to be the most energy-efficient response of olive trees to short-term salinity and drought. In contrast to proline and malondialdehyde, trends in superoxide dismutase activity suggest that it is a reliable indicator of salinity and drought stress. Regarding olive adaptability to salinity stress, promising results obtained with two wild olive genotypes merit their further physiological study.

Hydroxytyrosol isolation, comparison of synthetic routes and potential biological activities.

Hydroxytyrosol (HT) is a polyphenol found in the olive plant (Olea europaea) that has garnered attention from the food, feed, supplement, and pharmaceutical industries. HT has evolved from basic separation and extraction to chemical and biocatalytic synthesis. The yield of HT can reach 1.93 g/L/h through chemical synthesis and 7.7 g/L/h through biocatalysis; however, both methods are subject to inherent limitations. Furthermore, the potential health benefits associated with HT have been highlighted, including its ability to act as an antioxidant, reduce inflammation, combat cancer and obesity, and exert antibacterial and antiviral effects. Its neuroprotective effects, skin protection, and wound healing capabilities are also discussed. Given these remarkable biological properties, HT stands out as one of the most extensively investigated natural phenols. This review highlights future methods and pathways for the synthesis of HT, providing insights based on its bioactivity characteristics, health benefits, and potential future applications.

Soil water dynamics and olive yield (Olea europaea L.) under different surface drip irrigation treatments in northern Mediterranean

Soil water dynamics and olive yield (Olea europaea L.) under different surface drip irrigation treatments in northern Mediterranean

Bioaccumulation of pesticides in carabid beetles in a vineyard and olive grove under integrated pest management

Bioaccumulation of pesticides in carabid beetles in a vineyard and olive grove under integrated pest management

Effects of arbuscular mycorrhizal fungi in the rhizosphere of two olive (Olea europaea) varieties Arbequina and Barnea under water deficit conditions.

One strategy to improve olive (Olea europaea ) tree drought tolerance is through the symbiosis of arbuscular mycorrhizal fungi (AMF), which helps alleviate water deficit through a combination of morphophysiological effects. Cuttings of olive varieties Arbequina (A) and Barnea (B) were grown with (+AMF) or without (-AMF) inoculum in the olive grove rhizosphere soil. One year after establishment, pots were exposed to four different water regimes: (1) control (100% of crop evapotranspiration); (2) short-period drought (20days); (3) long-period drought (25days); and (4) rewatering (R). To evaluate the influence of AMF on tolerance to water stress, stem water potential, stomatal conductance and the biomarkers for water deficit malondialdehyde, proline, soluble sugars, phenols, and flavonoids were evaluated at the end of the irrigation regimes. Stem water potential showed higher values in A(+) and B(+) in all water conditions, and the opposite was true for stomatal conductance. For proline and soluble sugars, the stem water potential trend is repeated with some exceptions. AMF inoculum spore communities from A(+ and -) and B(+ and -) were characterised at the morphospecies level in terms of richness and abundance. Certain morphospecies were identified as potential drought indicators. These results highlight that the benefits of symbiotic relationships between olive and native AMF can help to mitigate the effects of abiotic stress in soils affected by drought.

Evaluation of the effect of agroclimatic variables on the probability and timing of olive fruit fly attack.

Agroclimatic variables may affect insect and plant phenology, with unpredictable effects on pest populations and crop losses. Bactrocera oleae Rossi (Diptera: Tephritidae) is a specific pest of Olea europaea plants that can cause annual economic losses of more than one billion US dollars in the Mediterranean region. In this study, we aimed at understanding the effect of olive tree phenology and other agroclimatic variables on B. oleae infestation dynamics in the Umbria region (Central Italy). Analyses were carried out on B. oleae infestation data collected in 79 olive groves during a 7-year period (from 2015 to 2021). In July-August, B. oleae infestation (1% attack) was negatively affected by altitude and spring mean daily temperatures and positively by higher winter mean daily temperatures and olive tree cumulative degree days. In September-October, infestation was negatively affected by a positive soil water balance and high spring temperatures. High altitude and cumulative plant degree days were related to delayed attacks. In contrast, high winter and spring temperatures accelerated them. Our results could be helpful for the development of predictive models and for increasing the reliability of decision support systems currently used in olive orchards.

Effectiveness of four Turkish entomopathogenic nematode isolates against Bactrocera oleae (Diptera: Tephritidae) pupae at different temperatures

Türkiye, is the country of origin of the olive tree and is among the world’s leading olive producers. Most of the olive production in Türkiye is concentrated in Izmir, Aydın, Çanakkale, Balıkesir, Muğla and Bursa Provinces. Bactrocera oleae (Diptera: Tephritidae), being one of the main pests of olive trees, is an important problem in olive cultivation in Türkiye. The efficacy of four Turkish populations of entomopathogenic nematodes against B. oleae pupae was determined under laboratory conditions. They were Steinernema feltiae/12, S. carpocapsae/1133, Heterorhabditis bacteriophora/70, H. bacteriophora/91, which were collected in different regions of Türkiye during our earlier studies. They were tested against the pest by using a single dose at 5 different temperatures (10, 15, 20, 25 and 30 °C). The highest infection rate was observed forH. bacteriophora/91 isolate at 25 °C, and the lowest infection rate was observed for S. feltiae/12 isolate at 10 °C.

The Status and Distributions of the Wild Olive (Olea europaea subsp. europaea var. sylvestris) in Muğla Province and Its Islands under Global Climate Change

The Status and Distributions of the Wild Olive (Olea europaea subsp. europaea var. sylvestris) in Muğla Province and Its Islands under Global Climate Change

Environment-dependent and intraspecific variations in leaf and size traits of a native wild olive (Olea europaea L.) along an aridity gradient in Morocco: a functional perspective

Environment-dependent and intraspecific variations in leaf and size traits of a native wild olive (Olea europaea L.) along an aridity gradient in Morocco: a functional perspective

Indigenous Medicinal Plants Used in the Management of Diabetes in Africa: 5 Years (2019-2024) in Perspective.

(1) Background: The utilization of medicinal plants in the management of diabetes is of great importance to the health of the indigenous population on the African continent. The high cost of orthodox conventional medicines coupled with the perceived side effects encourages the high patronage of indigenous medicinal plants in the management of this metabolic disorder. We conducted a review on the indigenous African medicinal plants that could be useful in preclinical and clinical trials in the field of diabetes mellitus research. (2) Methods: Data were mined from research articles published and associated with the use of medicinal plants in the management of diabetes on the African continent (from January 2019 to March 2024). Literature from ethnobotanical studies on the African continent was searched from the Google Scholar, SCOPUS, Medline, Web of Science and PubMed databases. We employed the following keywords: "indigenous plants", "diabetes in Africa" and "antidiabetic effect of medicinal plants". (3) Results: A total of 52 medicinal plants belonging to 31 families were recorded in this study. Amaryllidaceae (14.28%), Fabaceae (9.52%) and Asteraceae (9.52%) were the most cited plant families. The frequently used indigenous medicinal plants on the African continent were Allium sativum L. (n = 6), Olea europaea L. (n = 6), Azadirachta indica A. Juss (n = 5), Allium cepa L. (n = 5) and Moringa oleifera Lam. (n = 5). The highly cited parts of the plant used in the management of diabetes were the leaves (45.55%), bark (14.44%) and bulbs (12.22%). The preferred methods of the preparation of herbal medicines were decoction (45.23%) and infusion (25%). Oral (52.32%) was the preferred route of the administration of herbal medicine on the African continent. (4) Conclusions: The data revealed some similarities in the way countries on the African continent manage diabetes. This interesting observation will assist in our quest towards obtaining a standardized protocol using indigenous medicinal plants to combat diseases on the African continent.

Factors Affecting Water Deprivation Resistance in Bactrocera oleae (Olive Fruit Fly)

Factors Affecting Water Deprivation Resistance in Bactrocera oleae (Olive Fruit Fly)

Systemic/Immune-Modulation of Olea europaea Leaf Extract in Fetuses of Alloxan-Induced T1 Diabetic Rats.

Maternal glucose is the principal macronutrient that sustains fetal growth. Prolonged exposure of the fetus to hyperglycemia from the early stages of pregnancy accelerates the maturation of the stimulus-secretion coupling mechanism in β cell autoimmunity, which leads to early hyperinsulinemia in type 1 diabetes mellitus (T1DM). Nowadays, diabetes mellitus (DM) is the most common medical complication of pregnancy, and among young women, the prevalence of overt diabetes and undiagnosed hyperglycemia is rising. Even though conventional medication is effective in treating DM, it is expensive and has harmful side effects. Herbal medicine will thus incorporate alternative therapy and be more effective and less toxic. Due to their bioactive components, olive leaves (Olea europaea) are frequently used medicinally; however, little is known about how this plant affects the immune system when it comes to diabetes. The current study used a pregnant mother rat model of alloxan-induced T1DM to examine the antidiabetic properties and embryonic safety of olive leaves. Forty adult female Sprague Dawley rats were split up into four groups as follows: nondiabetic, diabetic, olive, and diabetic-olive groups. All the mother rats were sacrificed on the 20th day of pregnancy, and fetuses were collected for further investigations. In diabetic pregnant mothers, fetuses had systemic modulation-negative effects. These effects were significantly reversed when the diabetic groups were supplemented with extracts from olive leaves. The findings showed that the olive leaf extract inhibits the diabetogenic effect mediated by alloxan with effective and protective systemic immunomodulation during embryonic development.

Assessing Soil and Land Suitability of an Olive–Maize Agroforestry System Using Machine Learning Algorithms

Exponential population increases are threatening food security, particularly in mountainous areas. One potential solution is dual-use intercropped agroforestry systems such as olive (Olea europaea)–maize (Zea mays), which may mitigate risk by providing multiple market sources (oil and grain) for smallholder producers. Several studies have conducted integrated agroforestry land suitability analyses; however, few studies have used machine learning (ML) algorithms to evaluate multiple variables (i.e., soil physicochemical properties and climatic and topographic data) for the selection of suitable rainfed sites in mountainous terrain systems. The goal of this study is therefore to identify suitable land classes for an integrated olive–maize agroforestry system based on the Food and Agriculture Organization (FAO) land suitability assessment framework for 1757 km2 in Khyber Pakhtunkhwa province, Pakistan. Information on soil physical and chemical properties was obtained from 701 soil samples, along with climatic and topographic data. After determination of land suitability classes for an integrated olive–maize-crop agroforestry system, the region was then mapped through ML algorithms using random forest (RF) and support vector machine (SVM), as well as using traditional techniques of weighted overlay (WOL). Land suitability classes predicted by ML techniques varied greatly. For example, the S1 area (highly suitable) classified through RF was 9%↑ than that of SVM, and 8%↓ than that through WOL. The area of S2 (moderately suitable) classified through RF was 18%↑ than that of SWM and was 17%↓ than the area classified through WOL; similarly, the S3 (marginally suitable) class area via RF was 27%↓ than that of SVM, and 45%↓ than the area classified through WOL. Conversely, the area of N2 (permanently not suitable class) classified through RF and SVM was 6%↑ than the area classified through WOL. Model performance was assessed through overall accuracy and Kappa Index and indicated that RF performed better than SVM and WOL. Crop suitability limitations of the study area included high elevation, slope, pH, and large gravel content. Results can be used for sustainable intensification in mountainous rainfed regions by expanding intercrop agroforestry systems in developing nations to close yield gaps.

Functionalized olive wood shell stone as a new revalorized agri-food waste active in organocatalysis

Olive wood shell stone has been used as an effective matrix for silanization and further anchoring of an organic probe such as 3-(5-chloro-anthraquinonylamino)propanoic acid (1). Covalent fixation of the anthraquinoid molecule was achieved by a “grafting to” silanization process with 3-aminopropyltrimethoxysilane (APTMS) followed by an amidation procedure. Ligand 1 was routinely characterized by multinuclear magnetic resonance (1H, 13C and 15N) and X-ray diffraction crystallography, while the new agri-food revalorized organocatalyst material was characterized by a number of analytical techniques such as granulometry, elemental analysis, thermogravimetry, differential scanning calorimetry, X-ray photoelectron spectroscopy, FTIR (ATR and DRIFT), moisture content, Karl-Fisher, ζ-potential and optical and fluorescence microscopy. The new revalorized material was assayed in the heterogeneous organocatalytic cyanosilylation of carbonyls compounds under very mild conditions with excellent yields and high recyclability under both presence and absence of solvent. Kinetic studies were also performed in order to understand the water uptake implications of this new organocatalyst.

Exogenous systemin peptide treatment in olive alters Bactrocera oleae oviposition preference

AbstractThe olive fruit fly, Bactrocera oleae (Rossi), is a key pest of the olive crop, whose control relies mostly on the use of insecticides. Plant peptides may represent a more environmentally-friendly tool to manage olive fly, due to their recognized role to activate and/or prime plant defence responses against pests. In this work, behavioural experiments (no-choice and two-choice) and analysis of volatile compounds were carried out to evaluate the impact of the exogenous application of the peptide systemin to olive tree on olive fly infestation, and to elucidate its mode of action to prime plant defence. The treatment of olive branches with 10 nM systemin showed to confer protection against olive fly, by reducing significantly the ovipositions (up to 3.0-fold) and the number of infested fruits (up to 2.9-fold) when compared to non-treated branches. This protective effect was even detected in neighbouring non-treated branches, suggesting the ability of systemin to trigger plant-to-plant communication. The deterrent activity of the primed olives was associated with the emission of the volatiles 2-ethyl-1-hexanol, 4-tert-butylcyclohexyl acetate and 1, 2, 3-trimethyl-benzene, which were negatively correlated with oviposition and fly infestation. Systemin has also showed to trigger the biosynthesis of specific volatiles (esters) in olives in response to fly attacks. Overall, the observed protection conferred by systemin against olive fly is likely due to the emission of specific volatiles that can act as a defence and/or as signalling molecules to upregulate the plant defence response. Thus, systemin represents a novel and useful tool to manage olive fruit fly.

Clustering olive oil mills through a spatial and economic GIS-based approach

Sicily ranks as the third-largest region in Italy for olive growing and olive oil production, holding the second position nationally regarding the number of active olive oil mills. This pioneering study integrates spatial and economic analyses to examine the geographical distribution of olive oil mills in Sicily and their relationship with the localization of olive groves. Using Local Indicators of Spatial Association (LISA), we conducted an advanced analysis of spatial patterns of olive oil mills, considering travel time on the road network. The adopted methodology addresses issues related to overestimation based on straight-line assumptions and the neglect of travel speed. Unlike traditional Euclidean distance approaches, our methodology provides a detailed understanding of the spatial relationships between olive oil mills and olive groves, revealing distinct patterns linked to elevation and proximity to olive groves. By linking profitability indicators with spatial clusters, we identify different thresholds of economic sustainability. Consequently, these findings contribute to a more comprehensive understanding of the olive oil industry, suggesting more environmentally sustainable practices. Policymakers, researchers, and industry stakeholders can leverage this knowledge to make informed decisions that foster the long-term sustainability of the olive oil sector.

Latest Topics Concerning Cognitive Impairment Related with Olive Oil, Fruits, Vegetables and Others

The authors focused on nutritional therapy, including low carbohydrate diets (LCD), calorie restriction (CR), lipids, olive oil, and other dietary studies. Recent topics on cognitive impairment related to olive oil, fruits, vegetables, and other factors were described with perspectives. A reverse relationship was observed between total fruit/vegetable intake and dementia risk in the elderly. In a study of 92,383 cases, an intake of more than 7g/day of olive oil showed a 28% decreased risk of dementia-related death. Dietary patterns may influence cognitive mechanisms. Among 8,692 elderly participants, lower odds ratios (OR) for cognitive impairment were found for a protein-enriched diet (PED) at 0.910 and an anti-inflammatory diet (AID) at 0.789.

Exploring Plant-Derived Bioactive Compounds in Olea Europaea L. Leaves as Potent Inhibitors of PTP-1B Using an In silico Approach

In this study, we focus on exploring the medicinal potential of Olea Europaea L., a commonly used plant with diverse indigenous medicinal applications. The main aim is to identify promising phytoconstituents from Olea Europaea L. leaves that can act as inhibitors for the PTP-1B target, utilizing an in silico approach. The phytoconstituents were sourced from the IMMPAT database, and molecular docking was employed to assess their binding affinities. The docking results revealed that rutin (−10.05 kcal/mol) and quercetin (−8.28 kcal/mol) displayed the highest binding scores against PTP-1B, outperforming reference compounds. Furthermore, MM-GBSA calculations indicated favorable free binding energy. To ensure stability, 200 ns Molecular Dynamics simulations were conducted on the 2QBS-Rutin complex. The results revealed that the 2QBS-Rutin complex showed stable conformation throughout the simulation, maintaining consistency with RMSD values below 1 Å. This study highlights rutin and quercetin as promising phytoconstituents from Olea Europaea L. leaves, demonstrating potent-binding affinities against PTP-1B inhibitors.

Comparative transcriptome provides new insights into the molecular regulation of olive trees to chilling stress.

Olive (Olea europaea L.), an economically important oil-producing crop, is sensitive to low temperature, which severely limits its productivity and geographical distribution. However, the underlying mechanism of cold tolerance in olive remains elusive. In this study, a chilling experiment (4°C) on the living saplings of two olive cultivars revealed that O. europaea cv. Arbequina showed stronger cold tolerance with greater photosynthetic activity compared with O. europaea cv. Leccino. Transcriptome analyses revealed that early light-inducible protein 1 (ELIP1), the main regulator for chlorophyll synthesis, is dramatically induced to protect the photosynthesis at low temperatures. Furthermore, weighted gene co-expression network analysis, yeast one-hybrid and luciferase assays demonstrated that transcription factor bHLH66 serves as an important regulator of ELIP1 transcription by binding to the G-box motif in the promoter. Taken together, our research revealed a novel transcriptional module consisting of bHLH66-ELIP1 in the adaptation of olive trees to cold stress.

Human α-glucosidase inhibition and phytochemical profile of natural and shinzuke treated olives: implications from the processing method

Olive (Olea europaea) phytochemicals are associated with a reduced risk of type 2 diabetes. Table olives typically have higher phytochemical concentrations than olive oil, but their impact on human intestinal α-glucosidase is largely unknown. Shinzuke, the most common trade preparation in Japan, are alkali-treated non-fermented green olives. In contrast, natural olives are debittered by brining, which may enhance phytochemical retention. We evaluated the α-glucosidase inhibitory effect of Shinzuke and natural green olives produced in-house and compared them with commercial table olives. Eight types of table olives were tested against human intestinal α-glucosidase. Shinzuke Mission was the least effective (IC50 0.710 ± 0.058 mg/mL), while Natural green olives showed double to triple activity, with a non-competitive mechanism. Natural table olives retained more phytochemicals than shinzuke and other treated olives, and are good inhibitors of human α-glucosidase in vitro, exhibiting potential as a functional food for the management of postprandial glycaemia.Graphical