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Angjelina Belaj - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of early vigor traits in Wild Olive germplasm
Scientia Horticulturae, 2020Co-Authors: Lorenzo León, Angjelina Belaj, Raúl De La Rosa, P. Díaz-rueda, C. Carrascosa, José M. Colmenero-floresAbstract:Abstract The control of the Olive tree vigor is a critical factor to ensure adequate production and longevity of high-density Olive cultivation. To deal with this problem, we intend to take advantage of the genetic variability present in the Wild subspecies of Olea europaea to identify genotypes of reduced vigor with optimal adaptability to diverse soils and adverse environmental conditions. In this work, early vigor traits have been characterized in different Wild Olive subspecies that could potentially be used as rootstocks to control the vigor of grafted cultivars. Significant differences between genotypes were obtained for all vigor traits and high values of broad sense heritability were obtained for most of them, indicating strong genetic effect and therefore good possibilities for selection. Compared to ‘Arbequina’ and ‘Picual’ cultivars, some of the Wild genotypes evaluated showed a clearly lower vigor at the end of the experimental period. These genotypes could be tested as dwarfing rootstocks for high-density Olive plantations.
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Pre-breeding for resistance to Verticillium wilt in Olive: Fishing in the Wild relative gene pool
Crop Protection, 2015Co-Authors: Rocío Arias-calderón, Raúl De La Rosa, Lorenzo León, Dolores Rodríguez-jurado, José Bejarano-alcázar, Angjelina BelajAbstract:Abstract This study aimed to identify new sources of resistance to Verticillium wilt in Olive. We evaluated various types of genotypes: Wild Olive trees ( Olea europaea subsp. europaea var. sylvestris ), genotypes belonging to related subspecie ( Olea europaea subsp. guanchica ) and genotypes coming from crosses between Picual cultivar and Wild Olive trees. Fifty-six genotypes were inoculated by dipping roots and then screened under controlled conditions to test their resistance to a highly virulent Defoliating isolate of Verticillium dahliae . Picual (susceptible) and Frantoio (resistant) were control cultivars. Wide variability and significant differences were obtained in the evaluated disease parameters. The Relative Susceptibility Index (RSI), summarizing the disease parameters, was used for final classification of genotypes. Thirteen genotypes were categorized as resistant: eight Wild Olives from different locations, two genotypes belonging to subsp. guanchica populations from Canary Islands and three genotypes obtained from one of the crosses Picual x Wild. The identification of high levels of resistance to V. dahliae among Wild Olive genotypes may be helpful for the management of this disease. The resistant genotypes could be used as rootstocks for susceptible Olive cultivars or parents in future breeding programs.
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Utility of Wild germplasm in Olive breeding
Scientia Horticulturae, 2013Co-Authors: Tatjana Klepo, Raúl De La Rosa, Zlatko Šatović, Lorenzo León, Angjelina BelajAbstract:Abstract Olive breeding programs are only based on commercial cultivars as genitors. However, due to its wide variability, Wild Olive gremplasm could represent an interesting source of genes for the obtention of new cultivars. With purpose of evaluating the utility of Wild Olives in breeding programs, two open pollinated progenies (o.p.), originated from a Wild Olive (Alga05) and the main Spanish Olive cultivar (Picual), were compared. Both progenies were analyzed by morphological descriptors, agronomical traits and SSR markers. The use of these 3 marker systems revealed great discrimination capacity, high level of morpho-agronomic and genetic diversity and their complementariness on the evaluation of these Olive progenies. As expected, for most of morpho-agronomical traits, ‘Picual’ o.p. progeny showed superior values in comparison to the Wild o.p. progeny. However, ‘Alga05′ Wild Olive progeny was more vigorous, with shorter juvenile period and more abundant flowering than ‘Picual’ o.p. For both progenies, PCA showed strong association between different agro-morphological traits (fruit and stone dimensions in Wild Olive progeny and fruit trait with oil content in ‘Picual’ progeny) which could facilitate the selection of the most appropriate traits for further evaluations, increasing thus, the efficiency of Olive breeding programs. Our results indicate that the use of Wild Olive as genitors in breeding programs may be useful for generating new genotypes with interesting characters.
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Variability of Wild Olives (Olea europaea subsp. europaea var. sylvestris) analyzed by agro-morphological traits and SSR markers
Scientia Horticulturae, 2011Co-Authors: Angjelina Belaj, Zlatko Šatović, Lorenzo León, Raúl De La RosaAbstract:The genetic diversity of Wild Olive trees sampled from eight different sites from two provinces of Andalusia (Cadiz and Jaen), Southern Spain, was evaluated by means of agro-morphological traits and SSR markers. The agro-morphological traits showed a high variation between genotypes and significant correlation coefficients were obtained among the values recorded in two consecutive years, 2007/08 and 2008/09 (r = 0.59–0.78). Traits such as fruit symmetry (position A), stone shape, fruit flesh/stone ratio and Olive oil content on both wet and dry matter, showed the highest values of diversity and were very useful in genotype discrimination. As expected, average values obtained in Wild Olives for fruit size and oil content were lower than the previously reported in cultivated material. However, it is noticeable that Wild trees with fruit weights (1.3 g) and Olive oil percentage in dry matter (33.8%) comparable to the values found in some Olive cultivars, were also found. With both DNA-based and agro-morphological descriptors, higher levels of variability were found within each site than between sites. Genetic variation observed among the Wild Olive germplasm at the DNA level was higher than the agro-morphological traits, indicating the efficiency of SSR markers for detecting genetic diversity among Wild Olive genotypes and their relationships. The lack of consistency between the relationship studies performed with molecular and morphological markers could indicate that each marker system measures different aspects of the Wild Olive genetic variability. Molecular data obtained by SSR markers together with morphological and agronomical characterization of Olive trees confirmed the high diversity within the Wild populations and their potential use for Olive breeding.
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Genetic diversity and relationships of Wild and cultivated Olives at regional level in Spain
Scientia Horticulturae, 2010Co-Authors: Angjelina Belaj, Concepción Muñoz-díez, Luciana Baldoni, Zlatko Šatović, Diego BarrancoAbstract:Genetic diversity and relationships between local cultivars and Wild Olive trees from three important Spanish Olive-growing regions, Andalusia (South), Catalonia and Valencia (from Eastern Mediterranean Coastal area), were studied by means of eight SSR loci. Distinct allelic composition and heterozygosity levels were found in Wild Olive populations and cultivars. The observed patterns of genetic variation revealed: a) the independent clustering of Andalusian Wild Olives in a separate gene pool, b) the belonging of Wild populations and most cultivars from Catalonia to another gene pool, c) the joined clustering of Andalusian and a set of Valencian cultivars in a third gene pool, and d) clustering of Wild individuals from Valencia to the three different gene pools. These results suggest that Wild populations of Andalusia may represent true oleasters, the ones from Catalonia may be feral forms derived from cultivar seed spreading, while the population of Valencia seems to be the most admixed one. The significant differentiation between Andalusian and most Catalonian cultivars is indicating an independent selection of Olive cultivars in the two regions. The detection of a certain Wild genetic background in some Catalonian and Valencian cultivars and the similarity found between Wild and cultivated forms may suggest the use of local Wild trees in Olive domestication. The proposed scenario for the development of Olive cultivars in Andalusia includes an empirical selection of outstanding local Wild genotypes followed by various generations of crosses and various replanting campaigns, as well as possible introductions of ancestral cultivars. Therefore, our findings would lead us to support the hypothesis that the current diversity found in Spanish Olive cultivars may be regionally differentiated and due to both, autochthonous and allochthonous origin. The information obtained in this work gives insights into the genetic resources of the main Olive producing country, demonstrating that Wild Olive populations and local cultivars both represent potential sources of useful variability for Olive breeding programs.
Thomas Geburek - One of the best experts on this subject based on the ideXlab platform.
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Molecular diversity and gene flow within and among different subspecies of the Wild Olive (Olea europaea L.): A review
Flora, 2019Co-Authors: Alemayehu Kassa, Heino Konrad, Thomas GeburekAbstract:Abstract Six subspecies are currently recognized in the Wild Olive (Olea europaea L.): cuspidata, europaea, laperrinei, maroccana, cerasiformis, and guanchica. These occur in different natural distribution ranges in Europe, Africa, and Asia. Here we present an overview and summary of the accumulated information on the molecular diversity and gene flow in the species. Past climatic oscillations and geographical barriers have been identified to govern the pattern of genetic diversity and gene movement within and between taxa. Seed dispersal by animals and cultivar transport over vast geographical distances by man are important factors which have prevented the complete differentiation of subspecies. Available evidence has shown that subsp. cuspidata is the early diverging taxon of the Olive complex. However, results were not fully consistent concerning the relationships between the other subspecies. Molecular studies using nuclear and cytoplasmic markers show that the oleasters (subsp. europaea var. sylvestris) are ancestors to the cultivated forms (subsp. europaea var. europaea). However, due to hybridization in geographical proximate regions sometimes other subspecies also have influenced the cultivars. This complex process has blurred the domestication history of the species. The Wild relatives of the cultivated Olive are endangered in many parts of their range, albeit being important for forest restoration. Overall, molecular studies have answered a number of important questions, but most of the genetic studies so far focused on the Mediterranean oleasters, while the widespread cuspidata has not been sufficiently investigated. Using genomic approaches to understand the pattern of genetic variation will be helpful to solve open questions. Moreover, future genetic studies should focus on quantifying the local effects of disturbance factors on genetic diversity and mating system parameters of Wild Olive.
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Mating pattern and pollen dispersal in the Wild Olive tree (Olea europaea subsp. cuspidata)
Tree Genetics & Genomes, 2017Co-Authors: Alemayehu Kassa, Heino Konrad, Thomas GeburekAbstract:In this study, the mating system, contemporary pollen flow, and landscape pollen connectivity of the Wild Olive tree (Olea europaea subsp. cuspidata) were analyzed in a fragmented landscape of less than 4-km diameter located in north-western Ethiopia. Four remnant populations of different sizes were investigated. Eight highly polymorphic microsatellite markers were used to genotype 534 adults and 704 embryos. We used contrasting sampling schemes and different methodological approaches to analyze the pollen flow. We observed a lower rate of inbreeding and correlated mating in the fragmented vs. the non-fragmented subpopulation. Using parentage analysis, we detected a bidirectional pollen movement across subpopulations. Pollen flow was found to be directed towards small subpopulations based on parentage and anisotropic analysis. Pollen immigration amounted to more than 50%. Although most pollination occurred within a distance of less than 200 m, longer distance pollen movements of more than 3 km were also detected. Pollen dispersal in the large and dense subpopulation was reduced, and a smaller number of effective pollen sources were detected compared to a smaller fragmented subpopulation. We obtained consistent estimates for the number of effective pollen donors (approximately 6 per mother tree) using three different methods. The average pollen dispersal distance at the landscape level amounted to 276 m while at the local level, 174 m was estimated. Bigger trees were better pollen contributors than smaller trees. We showed here for the first time that pollen dispersal in Wild Olive follows a leptokurtic distribution.
Mokhtar Zarrouk - One of the best experts on this subject based on the ideXlab platform.
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Tunisian Wild Olive (Olea europaea L. subsp. oleaster) oils: Sterolic and triterpenic dialcohol compounds
Industrial Crops and Products, 2018Co-Authors: Bechir Baccouri, Hédia Manai, Jacinto Sánchez Casas, Emilio Osorio, Mokhtar ZarroukAbstract:Abstract The aim of the present investigation is to discriminate seven selected Wild Olive trees by studying their sterol and triterpenic dialcohol compositions with those of VOOs obtained from Chemlali and Chetoui Olive cultivars, all growing in the in the same pedoclimatic conditions. The main sterol found in all the samples is β Sitosterol, followed by Δ5-avenasterol These two major sterols are strongly and negatively correlated, and there is a clear differentiation between cultivars. Thus, MAT22 oleaster shows the highest value for β-sitosterol (87.18%), whereas SB12 oleaster is characterised by the lowest percentage of β-sitosterol (71%) and the highest one of Δ5-avenasterol (21.73%). For the remaining varieties, the levels of b-sitosterol and Δ-5-avenasterol are within the range of 74–86% and 4–17%, respectively. Two triterpenic dialcohols (erythrodiol and uvaol), were also detected besides the sterolic components. Sterol content of oils was below the upper legal limit of 4% in all nalysed samples, with a range from 1.05% to 3.40%. The statistical analyses (PCA and HCA) can explain the variability of the oil composition according to the cultivar. We note a good discrimination between varieties according to sterol and triterpenic dialcohol data. These components seem to be an effective tool to discriminate between the oleasters.
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Wild Olive (OLEA EUROPAEA L.) SELECTION FOR QUALITY OIL PRODUCTION
Journal of Food Biochemistry, 2010Co-Authors: Bechir Baccouri, Mokhtar Guerfel, Wissem Zarrouk, Wael Taamalli, Douja Daoud, Mokhtar ZarroukAbstract:ABSTRACT One hundred and fifty accessions belong to six Wild Olive populations from Tunisia were analyzed using fruit pomological traits and oil chemical characteristics. Analysis of variance revealed significant differences among Olive accessions for the main studied parameters, indicating a high degree of variability among oleasters. Cluster analysis revealed no clear relationships between accessions according to their geographical origin. Among the screened oleasters, three stand out for their interesting oil parameters, as compared to traditional varieties with high oleic and low linoleic acid contents, high triolein level, large total phenol content, high oxidative stability and high oil content. ZI2 had the highest values of oleic acid (78.5%), whereas H3 was noteworthy for its higher content of phenolic compounds (435.3 mg/kg). Accordingly, oil from H3 presented the highest oxidative stability (83.5 h). A significant relationship was observed between phenolic compounds and oxidative stability. PRACTICAL APPLICATIONS The identification of new cultivars and their oil composition is a key point in the improvement of Olive oil production. This is the first study of chemical composition of virgin Olive oils from Wild Olives. The paper is a study on the quality characteristics of Olive oils obtained from Wild Olive trees growing in Tunisia to define new cultivars well adapted to Tunisian environment and yielding high quality oils. Although the study was carried out in Tunisia, it might be applied to other countries with Wild Olive trees, in order to contrast productivity and oil quality with those resulting from native cultivars and transplanted foreign varieties.
Rafael M. Jiménez-díaz - One of the best experts on this subject based on the ideXlab platform.
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Verticillium dahliae inoculation and in vitro propagation modify the xylem microbiome and disease reaction to Verticillium wilt in a Wild Olive genotype
2020Co-Authors: Manuel Anguita-maeso, José L. Trapero-casas, Juan A. Navas-cortés, Rafael M. Jiménez-díaz, Concepción Olivares-garcía, D. Ruano-rosa, Elena Palomo-ríos, Blanca B. LandaAbstract:Host resistance is the most practical, long-term and economically efficient disease control measure for Verticillium wilt in Olive caused by the xylem-invading fungus Verticillium dahliae (Vd), and it is at the core of the integrated disease management. Plant9s microbiome at the site of infection may have an influence on the host reaction to pathogens; however, the role of xylem microbial communities in the Olive resistance to Vd has been overlooked and remain unexplored to date. This research was focused on elucidating whether in vitro Olive propagation may alter the diversity and composition of the xylem-inhabiting microbiome and if those changes may modify the resistance response that a Wild Olive clone shows to the highly virulent defoliating (D) pathotype of Vd. Results indicated that although there were differences in microbial communities among the different propagation methodologies, most substantial changes occurred when plants were inoculated with Vd, regardless whether the infection process took place, with a significant increase in the diversity of bacterial communities when the pathogen was present in the soil. Furthermore, it was noticeable that Olive plants multiplied under in vitro conditions developed a susceptible reaction to D Vd, characterized by severe wilting symptoms and 100% vascular infection. Moreover, those in vitro propagated plants showed an altered xylem microbiome with a decrease in total OTU numbers as compared to that of plants multiplied under non-aseptic conditions. Overall, 10 keystone bacterial genera were detected in Olive xylem regardless infection by Vd and the propagation procedure of plants (in vitro vs nursery), with Cutibacterium (36.85%), Pseudomonas (20.93%), Anoxybacillus (6.28%), Staphylococcus (4.95%), Methylobacterium-Methylorubrum (3.91%), and Bradyrhizobium (3.54%) being the most abundant. Pseudomonas spp. appeared as the most predominant bacterial group in micropropagated plants and Anoxybacillus appeared as a keystone bacterium in Vd-inoculated plants irrespective of their propagation process. Our results are first to show a breakdown of resistance to Vd in a Wild Olive that potentially maybe related to a modification of its xylem microbiome, and will help to expand our knowledge of the role of indigenous xylem microbiome on host resistance which can be of use to fight against main vascular diseases of Olive.
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Plant Regeneration via Somatic Embryogenesis in Mature Wild Olive Genotypes Resistant to the Defoliating Pathotype of Verticillium dahliae.
Frontiers in plant science, 2019Co-Authors: Isabel Narvaez, Rafael M. Jiménez-díaz, Carmen Martín, José A. Mercado, Fernando Pliego-alfaroAbstract:Regeneration capacity, via somatic embryogenesis, of four Wild Olive genotypes differing in their response to defoliating Verticillium dahliae (resistant genotypes StopVert, OutVert, Ac-18 and the susceptible one, Ac-15) has been evaluated. To induce somatic embryogenesis, methodologies previously used in Wild or cultivated Olive were used. Results revealed the importance of genotype, explant type, and hormonal balance in the induction process. Use of apical buds obtained from micropropagated shoots following a methodology used in cultivated Olive (4 days induction in liquid 1/2 MS medium supplemented with 30 µM TDZ-0.54 µM NAA, followed by 8 weeks in basal 1/2 MS medium) was adequate to obtain somatic embryos in two genotypes, StopVert and Ac-18, with a 5.0 and 2.5% induction rates, respectively; however, no embryogenic response was observed in the other two genotypes. Embryogenic cultures were transferred to basal ECO medium supplemented with 0.5 µM 2iP, 0.44 µM BA, and 0.25 µM indole-3-butyric acid (IBA) for further proliferation. Somatic embryos from StopVert were maturated and germinated achieving a 35.4% conversion rate. An analysis of genetic stability on StopVert, using Simple Sequence Repeats (SSRs) and Random Amplified Polymorphic DNA (RAPDs) markers, was carried out in embryogenic callus, plants regenerated from this callus and two controls, micropropagated shoots used as explant source, and the original mother plant. Polymorphism was only observed in the banding pattern generated by RAPDs in 1 of the 10 callus samples evaluated, resulting in a variation rate of 0.07%. This is the first time in which plants have been regenerated via somatic embryogenesis in Wild Olive.
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Characterization of resistance against the Olive‐defoliating Verticillium dahliae pathotype in selected clones of Wild Olive
Plant Pathology, 2016Co-Authors: Daniel Jiménez-fernández, José L. Trapero-casas, Blanca B. Landa, Juan A. Navas-cortés, Giovanni Bubici, M. Cirulli, Rafael M. Jiménez-díazAbstract:Verticillium wilt of Olive is best managed by resistant cultivars, but those currently available show incomplete resistance to the defoliating (D) Verticillium dahliae pathotype. Moreover, these cultivars do not satisfy consumers' demand for high yields and oil quality. Highly resistant rootstocks would be of paramount importance for production of agronomically adapted and commercially desirable Olive cultivars in D V. dahliae-infested soils. In this work, resistance to D V. dahliae in Wild Olive clones Ac-13, Ac-18, OutVert and StopVert was assessed by quantifying the fungal DNA along the stem using a highly sensitive real-time quantitative polymerase chain reaction (qPCR) protocol and a stem colonization index (SCI) based on isolation of V. dahliae following artificial inoculations under conditions highly conducive for verticillium wilt. Ac-13, Ac-18, OutVert and StopVert showed a symptomless reaction to D V. dahliae. The mean amount of D V. dahliaeDNA quantified in stems of the four clones ranged from 3.64 to 28.89 pg/100 ng Olive DNA, which was 249 to 1537 times lower than that in susceptible Picual Olive. The reduction in the quantitative stem colonization of Wild Olive clones by D V. dahliae was also indicated by a sharp decrease in the SCI. Overall, there was a pattern of decreasing SCI in acropetal progression along the plant axis, as well as correlation between positive reisolation and quantification of pathogen DNA. The results of this research show that Wild Olive clones Ac-13, Ac-18, OutVert and StopVert have a valuable potential as rootstocks for the management of verticillium wilt in Olive.
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Infection by Meloidogyne javanica does not breakdown resistance to the defoliating pathotype of Verticillium dahliae in selected clones of Wild Olive
Scientia Horticulturae, 2016Co-Authors: Juan E. Palomares-rius, Pablo Castillo, José L. Trapero-casas, Rafael M. Jiménez-díazAbstract:Abstract Host-plant resistance is the most practical, long-term and economically efficient disease control measure for Verticillium wilt in Olive caused by the soil-borne fungus Verticillium dahliae, and it is the core of the integrated disease management. In Spain, Verticillium wilt has become a main concern for the Olive industry because of the widespread occurrence of a highly virulent, defoliating (D) pathotype. Available V. dahliae-resistant Olive cultivars show incomplete resistance to the D pathotype and do not satisfy consumers’ demand for high yields and oil quality as well as suitability for new environments and cultural practices in modern Olive production in Spain. Highly resistant rootstocks would be of paramount importance for production of agronomically-adapted and commercially-desirable Olive cultivars. Nevertheless, the validity of resistant rootstocks grafted with Verticillium wilt-susceptible Olive cultivars in soils highly infested with the D pathotype would be increased if the resistance is demonstrated stable in coinfection with plant-parasitic nematodes, such as root-knot nematodes. In this work, Wild Olive clones ‘Ac-4’, ‘Ac-13’ and ‘Ac-18’ previously developed as highly resistant to D V. dahliae were tested for infection response by the root-knot nematode Meloidogyne javanica alone and jointly with D V. dahliae under controlled conditions optimal for Verticillium wilt in Olive. The three Wild Olive clones showed resistance to D V. dahliae under high inoculum levels in soil and also when plants were co-infected by both pathogens. However, all clones were susceptible to M. javanica, although ‘Ac-13’ and ‘Ac-18’ showed a degree of tolerance to the used inoculum level. Nevertheless, coinfected plants with M. javanica and D V. dahliae reduced the nematode reproduction rate in ‘Ac-13’ and ‘Ac-18’, but increased that in ‘Ac-4’, suggesting that different resistance mechanisms to D V. dahliae might be operating in these clones were acting also on M. javanica reproduction.
Romain Larbat - One of the best experts on this subject based on the ideXlab platform.
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Quality, composition and antioxidant activity of Algerian Wild Olive (Olea europaea L. subsp. Oleaster) oil
Industrial Crops and Products, 2016Co-Authors: K. Bouarroudj, Abderezak Tamendjari, Romain LarbatAbstract:Abstract Wild Olive trees, also called oleasters, are largely distributed all around the Mediterranean basin. The objective of this study was to evaluate the quality, the composition and the antioxidant activity of four Algerian oleaster oils in comparison to an extra virgin Olive oil (EVOO) reference. Three of the four oleaster oils exhibited a composition in accordance to the extra virgin oil category. The total phenol, ortho -diphenol and tocopherol contents were equal to higher in the oleaster oils, than in the EVOO reference. Moreover, all the oleaster oils exhibited higher antioxidant properties than the EVOO reference. Interestingly, the phenolic composition of the oleaster oils differed greatly between samples. Two compounds usually not described in Olive oil were identified, namely eriodictyol and naringenin. Principal component analysis (PCA) applied to tocopherol and phenolic compounds showed clear variability between oil samples. Taken together, these results highlight the high potential of oleaster oil as a phytochemical resource, a possible alternative food and a genetic resource to improve the Olive oil quality.
