Memes Research Articles

Unveiling the Genetic Diversity of Tunisian Monumental Olive Trees to Enhance the Olive Sector

The centennial olive trees of Tunisia serve as enduring symbols of resilience, having withstood the test of time while witnessing the effects of climate change, rising temperatures, water scarcity, and the emergence of new diseases. Presently, there is a notable lack of research on the genomic analysis of ancient trees. This study investigates the genetic diversity of twenty-eight ancient olive specimens collected from archeological sites in nine governorates from the north to the south of Tunisia. Using nine highly polymorphic microsatellite markers, these ancient olive trees were compared with twenty-five local Tunisian cultivars and sixty olive varieties from other Mediterranean countries (Greece, Italy, and Spain). The ancient olive trees were revealed to have a high genetic diversity, with 67 alleles and a Shannon index of 1.68. The key findings identify the ancient trees M25, M1, M28, and M24 as synonyms for local olive cultivars, while “M10” is noted as a first-generation migrant from Tunisian olives. Cluster analysis methods, including structure, neighbor-joining (NJ), and principal coordinates (PCoA), show that these ancient trees share a common genetic background and ancestry with varieties from Tunisia, Italy, Spain, and Greece. The conservation and evaluation of these genotypes will increase the genetic diversity available for breeding programs and strengthen the resilience of agriculture, which is currently facing unprecedented pressure worldwide.

Olive Oil Quality Produced Under Conventional and Organic Farming Systems in a Multisite Two-Year Evaluation in Greece

Six olive groves (three conventional and three organic) of “Koroneiki” olive cultivar were selected in two different provinces in southern Greece during a two-year trial (one province per year). At harvest, the oil was extracted from olive fruits using an Abenchor-type olive mill. Olive oil quality characteristics, including free acidity, ultraviolet absorbance indexes, peroxide value, free fatty acids, total and individual phenolic compounds, antioxidant capacity, and α-tocopherol content, were assessed. During the second year, olive oil samples were stored for 12 months, and their quality was re-evaluated. Few significant differences were observed between organically and conventionally produced olive oils, while the quality of both deteriorated significantly after storage (decrease in antioxidant capacity and major phenolic compounds, except for hydroxytyrosol and tyrosol, and increase in peroxide index value). Principal component analysis revealed that, during the first year, oils produced following organic and conventional practices could be distinguished; however, this distinction was not evident during the second year. Nevertheless, significant differentiation was found between oils produced under the same cultivation practice. In conclusion, the discrepancies found in the literature regarding organic versus conventional olive oil properties probably originate from the differences detected even among similar products (organic or conventional), including high-standard deviations.

Optimizing decision-making potential, cost, and environmental impact of traps for monitoring olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae).

This work aimed to optimize olive fruit fly (OFF) Bactrocera oleae (Rossi) (Diptera: Tephritidae) monitoring and integrated management, thereby ensuring optimal and less-costly decision-making and timely intervention. Field trials in Andalusia (Spain) were undertaken over 2 years to optimize trap model, color, size, and density for the accurate determination of pest spatial distribution and damage as a function of olive cultivar. McPhail traps and yellow sticky panels outperformed the other 4 models with respect to the number of OFF captured. However, McPhail traps caught more natural enemies than yellow sticky panels and so sticky panels were selected to unravel the effect of color on the number of both OFF and natural enemies [hymenopteran parasitoids (Psyttalia concolor) and lacewings (Chrysopidae)] captured. Yellow sticky panels outperformed white, green, and blue ones for the number of OFF captured and captured the fewest natural enemies. When comparing the surface area of yellow sticky panels, 20 × 25 and 10 × 25cm double-sided panels were equally effective at catching OFF. However, large double-sided yellow sticky panels caught significantly more natural enemies than the small double-sided panels, a key result for developing a less costly and environmentally friendly monitoring system. Furthermore, it was shown that the damage curve had a cultivar-based shape, i.e., for the same population size of OFF the damage caused varied depending on cultivar. Finally, 15 sticky panels per hectare were the optimal number for estimation of OFF spatial distribution. The present research provides key information for new trap design, OFF forecasting, and IPM development.

Behavior of Olive Genotypes Against Quick Decline Syndrome (QDS) Caused by Xylella fastidiosa subsp. pauca in Apulia.

Xylella fastidiosa subsp. pauca (Xfp), a quarantine pathogen in the European Union, severely threatens Mediterranean olive production, especially in southern Italy, where Olive Quick Decline Syndrome (OQDS) has devastated Apulian olive groves. This study addresses the urgent need to identify resistant olive genotypes by monitoring 16 potentially tolerant genotypes over six years, assessing symptom severity and bacterial load. These genotypes, which survived in heavily infected areas, showed varied responses to Xfp; some maintained low symptom severity with minimal bacterial presence (high or undetectable Cq values), while others exhibited increased bacterial loads yet remained asymptomatic or showed limited canopy desiccation. SSR markers were used to investigate the genetic relationships among these genotypes and other widespread Mediterranean cultivars, showing genetic similarity with the resistant ones such as the Albanian Kalinjot and the Greek Leucocarpa, as well as with local Apulian cultivars, highlighting the potential of local and Mediterranean olive germplasm for Xfp resistance. This study integrates phenotypic responses with genetic knowledge to support the development of conservation strategies that will enhance the genetic diversity of Apulian olive cultivars. In addition, by focusing on the resilience of the different olive genotypes, this research aims to protect the traditional cultivars from the emerging threats, thus preserving the ecological and cultural heritage of the olive biodiversity of the Mediterranean region.

Variations on reproductive phenology, agroclimatic requirements, and biomass production of native and foreign olive (Olea europaea L.) cultivars under central northern Morocco climatic conditions

Variations on reproductive phenology, agroclimatic requirements, and biomass production of native and foreign olive (Olea europaea L.) cultivars under central northern Morocco climatic conditions

Fatty acid profiles and differential genes expression in Tunisian olive cultivars: a study of fruit ripening and quality attributes

Fatty acid profiles and differential genes expression in Tunisian olive cultivars: a study of fruit ripening and quality attributes

Fruit Growth and Oil Accumulation of Olive (Olea europaea L.) Cultivars at Different Locations Along a Latitudinal–Altitudinal Gradient

Environmental conditions during olive fruit development and genotype have shown to be important sources of variability in final fruit weight and oil concentration. There are fewer studies concerning how the environment and genotype modulate growth dynamics. Thus, the present study aimed to evaluate the timing of fruit growth, pit hardening, and oil accumulation in several olive cultivars under different air temperatures along a latitudinal gradient (29°–33° S) with a range of altitudes (450–1250 masl) in Western Argentina; determine parameters derived from the dynamics of fruit growth and oil accumulation along the same gradient; and explore possible relationships between derived parameters and air temperatures. The cultivars evaluated were Arbequina, Arbosana, Coratina, Changlot, and Picual. Pit hardening occurred 20 days earlier in warmer locations, leading to an earlier onset of oil synthesis. The final fruit dry weight was mainly influenced by the cultivar, which was explained by differences in fruit growth rates. Cooler locations had 39% higher average final fruit dry weight and 22% higher oil concentration than warmer ones. Differences in final oil concentration between genotypes × environments were primarily associated with the oil accumulation rate rather than the duration of the oil accumulation period. However, changes in this rate seem to be cultivar-dependent. Interestingly, the rate and oil accumulation duration showed a negative relationship. These results highlight the need to explore genetic variability in temperature response to limit the detrimental impacts of global warming on olive fruit growth and oil concentration.

Discrimination of Farming Practices Through Olive Leaf Phenolic and Mineral Analysis

The content and composition of phenolic compounds and mineral elements in olive leaves are susceptible to variation influenced by various factors, such as genotype, environment, and agricultural practices. The aim of this study was to investigate and compare the response of phenolics and minerals to organic and integrated farming systems. Trees from three olive cultivars grown in two neighboring olive groves with different farming systems were used. After sampling during pruning in two consecutives sampling years, the contents of phenolics and minerals in olive leaves was determined by high-performance liquid chromatography (HPLC) and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis, respectively. The obtained results revealed a complex response of both phenolics and minerals, strongly influenced by interactions among the factors, such as farming system, cultivar, and sampling year. Specific phenolic compounds, such as luteolin-4-O-glucoside and luteolin-7-O-glucoside, were particularly abundant under organic farming conditions. Others, like oleuropein and oleacein, followed a similar trend, though they were more strongly affected by different cultivar and sampling year combinations. A lower content of mineral elements was generally observed under organic farming conditions, although it was also significantly affected by cultivar and sampling year. The results of this study have the potential to be utilized for the enhanced production of organic olive leaves as a reliable source of valuable phytochemicals for nutraceuticals, functional foods, and dietary supplements.

Molecular and Biochemical Characterization of Olive 4-Hydroxyphenyl Pyruvate Dioxygenase Involved in the Biosynthesis of Tocopherols Present in Virgin Olive Oil.

Olive (Olea europaea) fruit contains high amounts of tocopherols that are responsible, along with secoiridoid phenolic compounds, for most of the antioxidant and anti-inflammatory properties of virgin olive oil. This study focuses on the molecular and biochemical characterization of olive 4-hydroxyphenyl pyruvate dioxygenase (OeHPPD) catalyzing the biosynthesis of homogentisic acid, which constitutes the phenolic residue in the tocopherol molecule. OeHPPD is a cytoplasmic enzyme with a molecular weight of 49.8 kDa and a predicted tertiary structure very similar to the Arabidopsis enzyme that suggests similar catalytic mechanisms. OeHPPD has an estimated Kcat of 75.26 s-1 and catalytic efficiency (Km/Kcat) of 0.145 μM-1 s-1 with 4-hydroxyphenyl pyruvate as the substrate. The expression analysis in fruits from selected olive cultivars harvested at different ripening stages indicates that the OeHPPD gene is temporally regulated and cultivar-dependent. Moreover, the analysis of OeHPPD expression in fruits affected by drought stress suggests that HPPD is involved in olive environmental adaptation.

Antiproliferative Activity of Antioxidants-Rich Extracts from Olea europaea L. Leaves and Oil Against Six Cancerous Human Cell Lines

ABSTRACT The present work aims to study the cytotoxic effect of the methanolic extract of leaves and oil of three olive cultivars: Manzanillo, Picual and Koronieki. Against six cancer cell lines, namely MCF-7 and MDA (breast cancer), HepG2 (liver cancer), PC3 (prostate cancer), Caco-2 (colon cancer), and A549 (lung cancer) using the MTT method. The results obtained showed that Manzanillo leaf methanolic extract (LMME) and Manzanillo oil (OMME) gave the highest cytotoxicity with the lowest IC50 against Caco2 and A549 cell lines. To explain this result, the mechanism of action was studied at the chemical, cellular and molecular levels. The chemical composition analysis of LMME and OMME was performed by GC-MAS. Furthermore, phytochemical analysis was performed. In addition to cell cycle analysis and apoptosis induction, the gene expression of three apoptotic genes was measured. The total phenolic contents (TPC) and total flavonoid contents (TFC) of (LMME) were greater than that of (OMME). Both LMME and OMME had arrested cell cycle at G1 phase for each of Caco2 and A549 cells. LMME and OMME induce up regulation of Casp3 and BAX genes and down regulation of Bcl-2 gene. These results indicated that, LMME and OMME had anti-proliferation effect against Caco2 and A549 cells through induction of apoptosis pathway. Further detailed studies are needed to examine the effect of each fraction of whole extract.

The Impact of Multimedia Art on Public Health Campaigns

Multimedia art has proven to be an effective tool for conveying public health messages, using mediums like VR installations, viral art, documentaries, and interactive media. This paper examines how multimedia art captures public attention and encourages engagement with health messages through creative and emotional resonance. By drawing on case studies, it examines how different forms of art such as posters, films, and public performances effectively break through media noise to reach diverse audiences. Ultimately, this analysis highlights the impact of multimedia art in improving message retention, community connection, and behavior change, presenting both the benefits and ethical considerations of using art to enhance public health efforts. Keywords: Public health campaigns, Multimedia art, Health communication, Community engagement, Health behavior change.

Micropropagation affects tree architecture of two olive cultivars: a field evaluation

Micropropagation affects tree architecture of two olive cultivars: a field evaluation

Exploring the Impact of High-Temperature Stress on Physiological, Anatomical, Molecular, Productive, and Quality Parameters in Diverse Olive Cultivars

Olive (Olea europaea L.) is one of the most important horticultural crops in Saudi Arabia. High temperatures are typical in most regions during the summer season. This study explored the effect of high temperatures on diverse olive cultivars (Manzanillo, Chemlali, and Picual) grown in three different geographical locations in Saudi Arabia (Sakaka, Basita, and Al-Qurayyat). Sakaka region was classified as a hot region, while the Basita and Al-Qurayyat regions were characterized by relatively mild or low temperatures. Genotypic components were assessed by studying Amplified Fragment Length Polymorphism (AFLP) molecular markers and physiological, anatomical, productive, and oil quality parameters. The evaluated genotypes displayed considerable variation across the three studied locations. Picual exhibited more heat tolerance, followed by Chemlali and Manzanillo. The high temperature in Sakaka negatively impacted critical characteristics related to olive growth, production, and quality. Results revealed that linoleic acid, oil acidity, total phenols, upper epidermis, palisade tissue, vascular bundle area, and mesophyll were the most appropriate parameters for predicting the impact of high temperatures. These traits were highly correlated with Sakaka and were highly and significantly associated with all the studied markers. Also, significant interactions between locations and genotypes showed that the means for most of the studied traits were the highest in Basita region.

Prediction of olive tuberculosis through physicochemical characterisation of Pseudomonas savastanoi and surfaces of different olive tree parts

ABSTRACT This study examined plant–microbe interactions and surface contamination of olive trees by Pseudomonas savastanoi pv. savastanoi, the pathogen causing olive tuberculosis. Using XDLVO theory, we assessed the theoretical adhesion of P. savastanoi B97 cells to the bark, upper, and lower leaf surfaces of four olive cultivars based on physicochemical properties. Contact angle measurements revealed that lower leaf surfaces were more hydrophobic than upper leaf and bark surfaces, with a stronger electron donor character observed on the latter two. Lower leaf surfaces were identified as the preferred site for bacterial adhesion because of higher hydrophobicity. Among the cultivars, Arbicuina DOC and Arbicuina were most susceptible to colonisation. Conversely, cultivars with lower hydrophobicity and stronger electron donor properties, such as Haouzia and Moroccan Picholine, demonstrated greater resistance. These findings suggest that evaluating these properties can inform disease control strategies, promoting sustainable agriculture through resistant cultivars or targeted management of vulnerable surfaces.

Hermaphrodite Flower Ratios and Fruit Drop in Some Olive Cultivars

The intricacies of flower biology in olive cultivars reveal variations in the occurrence of male and hermaphrodite flowers. This study endeavours to ascertain the frequency of hermaphrodite flowers over a three-year period within the ecological context of Tarsus/Mersin. Simultaneously, post-fertilization fruit abscission rates specific to each cultivar were determined. By initially quantifying flower numbers and subsequently comparing them against fruit retention rates, this research aimed to elucidate the impact of self-pollination and cross-pollination on fruit set across the examined cultivars. The period from the opening of flowers to the stage of fruit setting was found to range from 10 to 15 days. While the ratios of hermaphrodite flowers remained similar across years, the highest ratio was observed in the Domat cultivar, followed by the Sarı Ulak and Gemlik cultivars. Pollination experiments conducted on the Domat, Gemlik and Sarı Ulak cultivars revealed that fruit drop rates were highest in self-pollination practices. Conversely, foreign pollination practices resulted in lower fruit drop rates compared to self-pollination, indicating a positive impact of pollinator use on fruit retention.

Application of Liquid Chromatography-Ion Mobility Spectrometry-Mass Spectrometry-Based Metabolomics to Investigate the Basal Chemical Profile of Olive Cultivars Differing in Verticillium dahliae Resistance.

The limited effectiveness of current strategies to control Verticillium wilt of olive (VWO) prompts the need for innovative approaches. This study explores the basal metabolome of 43 olive cultivars with varying resistance levels to Verticillium dahliae, offering alternative insights for olive crossbreeding programmes. The use of an innovative UHPLC-ESI-TimsTOF MS/MS platform enabled the annotation of more than 70 compounds across different olive organs (root, stem, and leaf) and the creation of a preliminary compilation of TIMSCCSN2 experimental data for more reliable metabolite annotation. Moreover, it allowed the documentation of numerous isomeric species in the studied olive organs by resolving hidden compounds. Multivariate statistical analyses revealed significant metabolome variability between highly resistant and susceptible cultivars, which was further investigated through supervised PLS-DA. Key markers indicative of VWO susceptibility were annotated and characteristic compositional patterns were established. Stem tissue exhibited the highest discriminative capability, while root and leaf tissues also showed significant predictive potential.

Early evaluation of salt-stress tolerance of new released olive cultivars based on physiological and biomass allocation indicators

The evaluation of salt-tolerant olive tree genotypes released from breeding program has become intrinsic in order to develop sustainable agriculture in these regions. The current study aims to i) evaluate the tolerance of two new released olive cultivars (Zeitoun Ennour and Zeitoun Ennwader), issued from a Tunisian breeding program in comparison with the main olive cultivar ‘Chemlali Sfax’, and ii) identify suitable salt-tolerance indicators for this evaluation. The trial was conducted under controlled conditions in a greenhouse, for six months, and plants were irrigated with half-strength Hoagland nutrient solution containing NaCl at various levels (0, 75, 150 and 225 mM). Vegetative growth, biomass allocation and biochemical parameters were considered for the assessment of salt-tolerant capacity. Results revealed that growth and biomass should be considered as useful indicators for early evaluation method of salt-stress tolerance. ‘Chemlali Sfax’ displayed a gradual significant decrease of vegetative growth with increasing salinity. The reduction of shoot elongation and trunk diameter was most evidently at 150 mM with 43.2 % and 80.8 %, respectively. However, the new released cultivars showed unaffected vegetative growth, despite a slight decrease at the salt level of 225 mM. Moreover, results demonstrated the importance of certain physiological and biochemical indicators such as ions contents. The new released cultivars maintained a high K+/Na+ ratio at moderate salinity then a significant decrease occurred at 150 mM. In conclusion, vegetative growth, biomass allocation and K+/Na+ ratio seemed to be the suitable salt-tolerance indicators for early evaluation. Based on these indicators, ‘Zeitoun Ennour’ seems to be the most salt tolerant genotype and ‘Zeitoun Ennwader’ proves to have a similar salt tolerant capacity as ‘Chemlali Sfax’, which is a valuable information for olive growers in arid region.

High-resolution gene expression atlases of two contrasting major Greek olive (Olea europaea L.) tree cultivars for oil and table olive production.

Olive (Olea europea L.) is one of the most economically important tree crops worldwide, especially for the countries in the Mediterranean basin. Given the economic and nutritional importance of the crop for olive oil and drupe production, we generated transcriptional atlases for the Greek olive cultivars "Chondrolia Chalkidikis" and "Koroneiki" which have contrasting characteristics in terms of fruit development, oil production properties, and use. Our analysis involved 14 different organs, tissue types, and developmental stages, including young and mature leaves, young and mature shoots, open and closed flowers, young and mature fruits (epicarp plus mesocarp), young and mature endocarps, stalks, as well as roots. The developed gene expression atlases and the associated resources offer a comprehensive insight into comparative gene expression patterns across several organs and tissue types between significant olive tree cultivars. The comparative analyses presented in this work between the "Koroneiki" cultivar, which performs better in olive oil production, and the "Chondrolia Chalkidikis," which grows larger fruits, will be essential for understanding the molecular mechanisms underlying olive oil production and fruit shape and size development. The developed resource is also expected to support functional genomics and molecular breeding efforts to enhance crop quality and productivity in olive trees. The transcriptome data were generated using paired-end Illumina Next-Generation Sequencing technologies. The sequencing yielded approximately 13 million reads per sample for "Chondrolia Chalkidikis" and around 24 million reads per sample for "Koroneiki." The transcriptomes were comparatively analyzed to reveal tissue-specific and differentially expressed genes and co-expression gene modules within and between cultivars. The comparative analysis unveiled tissue-specific and differentially expressed genes within and between cultivars. Hierarchical gene clustering revealed intra- and inter-cultivar expression patterns, particularly for the endocarp and fruit tissues relevant to olive oil production and fruit development. Additionally, genes associated with oil production and fruit size/shape development, including those in fatty acid metabolism and developmental regulation, were identified. To facilitate accessibility, the GrOlivedb (www.GrOlivedb.com) database was developed, housing the comprehensive transcriptomic data for all of the analyzed organs and tissue types per cultivar. This resource will be a useful molecular tool for future breeding studies in olive oil production and fruit development and a valuable resource for crop improvement.

Occurrence of Cold Damage in Several Olive Cultivars in Coastal Area of Gyeongsangnam-do and at Different Low Temperatures

Occurrence of Cold Damage in Several Olive Cultivars in Coastal Area of Gyeongsangnam-do and at Different Low Temperatures

Morphological, physiological, and biochemical responses of some olive tree cultivars to low temperature stress

Morphological, physiological, and biochemical responses of some olive tree cultivars to low temperature stress