Survey of over 4, 500 monumental olive trees preserved on-farm in the northeast Iberian Peninsula, their genotyping and characterization

Inventorying, characterising and conserving on-farm ancient olive trees is a priority for safeguarding their genetic, natural and agricultural value and for protecting ancient genotypes threatened with extinction. In the “Taula del Sénia” (M-TdS) area (northeast Iberian Peninsula) a highly important cultural landscape has been preserved, in which the olive groves play an outstanding social and economic role: the ancient olive trees, sustained by many local farmers, constitute a living heritage and provide a clear example of High Nature Value (HNV). A total of 4526 ancient productive olive trees, with a trunk circumference (PBH) larger than 3.5 m, were inventoried and their spatial localization and biometric measurements were collected. 41 olive trees have shown the highest category in monumentality (PBH >8.1 m). The outstanding trees might be 634–1082 years old. The endocarp morphology of a representative sample of the most ancient trees from this settlement resulted in 14 different profiles. The ancient trees genotyped, through eight simple sequence repeat (SSR) markers, revealed 43 SSR profiles. The use of SSR enabled us to verify that most of the trees (98%) belong to the local cv. ‘Farga’, a male sterile variety with a rare chlorotype, only a few trees corresponded with other local varieties, ‘Morrut’, ‘Canetera’ and ‘Sevillenca’, and ten hitherto unidentified genotypes were distinguished, some with chloroplast lineages different from the ‘Farga’ type. The M-TdS area holds a unique living and exploitable heritage with the highest concentration of ancient olive trees worldwide. On-farm conservation of this germplasm by the community of local growers is enabling preservation of this important source of genetic variation, potentially holding traits of resilience and adaptation to adverse soil and climatic conditions, demonstrated by the survival of these trees over the centuries. Farmers have undertaken initiatives to valorize the olive oil deriving from these M-TdS trees.info:eu-repo/semantics/acceptedVersio

Ancient olive trees as a source of olive oils rich in phenolic compounds

Olive oil phenolic compounds are receiving increased attention due to its influence on sensory characteristics and to scientific evidences of positive health effects. In this work, 28 ancient olive trees were selected and, during four consecutive seasons (2014–2017), oils were extracted and their phenolic fraction characterized. Hydroxytyrosol and tyrosol secoiridoids were the predominant groups, with contents between 32 and 496 mg of tyrosol equivalents/kg. Based on principal component analysis it could be concluded that the individual phenolic contents enabled the unsupervised grouping of olive oils by crop year. Furthermore, linear discriminant analysis allowed achieving sensitivities greater than 90%. It was shown that some specimens consistently allowed obtaining oils with high phenolic contents (≥500 mg tyrosol equivalents/kg). The identification of centenarian specimens for breeding based on their potential to produce oils with high levels of healthy compounds is of utmost interest, contributing to preserve the genetic heritage.This work was financially supported by Strategic Project PEst-OE/ AGR/UI0690/2014 (CIMO), Project UID/QUI/50006/2013 (REQUIMTE-LAQV); and Project POCI-01-0145-FEDER-006984 (Associate Laboratory LSRE-LCM); all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. This work was also supported by PRODER project OliveOld – Identificação e caraterização de oliveiras centenárias para obtenção de produtos diferenciados” n° 53988. Nuno Rodrigues thanks FCT, POPHQREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio

Centennial olive trees as a reservoir of genetic diversity

Background and AimsGenetic characterization and phylogenetic analysis of the oldest trees could be a powerful tool both for germplasm collection and for understanding the earliest origins of clonally propagated fruit crops. The olive tree (Olea europaea L.) is a suitable model to study the origin of cultivars due to its long lifespan, resulting in the existence of both centennial and millennial trees across the Mediterranean Basin.MethodsThe genetic identity and diversity as well as the phylogenetic relationships among the oldest wild and cultivated olives of southern Spain were evaluated by analysing simple sequence repeat markers. Samples from both the canopy and the roots of each tree were analysed to distinguish which trees were self-rooted and which were grafted. The ancient olives were also put into chronological order to infer the antiquity of traditional olive cultivars.Key ResultsOnly 9·6 % out of 104 a priori cultivated ancient genotypes matched current olive cultivars. The percentage of unidentified genotypes was higher among the oldest olives, which could be because they belong to ancient unknown cultivars or because of possible intra-cultivar variability. Comparing the observed patterns of genetic variation made it possible to distinguish which trees were grafted onto putative wild olives.ConclusionsThis study of ancient olives has been fruitful both for germplasm collection and for enlarging our knowledge about olive domestication. The findings suggest that grafting pre-existing wild olives with olive cultivars was linked to the beginnings of olive growing. Additionally, the low number of genotypes identified in current cultivars points out that the ancient olives from southern Spain constitute a priceless reservoir of genetic diversity

Agritourism and territorial framework in the northern Salento (Apulia region, Italy)

The Territory Landscape Plan of the Apulia Region (PPTR)focuses on rural areas and agricultural sector, putting them in a holistic local and socio-economic context. This strategy isimplemented through the town-country pact, one of the five local projects proposed by the PPTR. The aim of the research is the study of the context and specificity of agritourism in Ostuni and Fasanocoastal areas (northern Salento), in which natural beauties, such as rural and coastal landscapes, coexist, characterized by ancient olive groves, historical rural houses and charming towns. In particular, the study analyses this rural context by means of the relationship between agritourism and territorial framework in order to check the sustainability of the development processes and their consistency with the programmatic guidelines of the PPTR. Qualitative approacheshas been used, such as semi-structured interviews and photographic material

Traditional Olive Tree Varieties in Alto Aragón (NE Spain): Molecular Characterization, Single-Varietal Oils, and Monumental Trees

Recovering minority olive tree varieties helps preserve genetic diversity and contributes to sustainable agriculture practices. The International Olive Council has recognized the importance of conserving olive tree genetic resources and the European Union’s Horizon Europe program has identified the preservation of crop diversity as a priority for sustainable food systems. In the work presented herein, old olive groves in the province of Huesca (NE Spain), managed according to the traditional model, were surveyed, sampled, and analyzed using molecular characterization techniques (based on EST-SNPs markers). Twenty-nine new varieties were identified and deposited in IFAPA’s World Germplasm Bank of Olive Varieties. In the first step towards their valorization, eight single-varietal oils from Alto Aragon varieties were produced and characterized, and their organoleptic properties were evaluated, paving the way for the production of differentiated quality oils. Furthermore, ancient olive trees were selected and 3D scanned to promote their protection as singular or monumental trees and for oleo-tourism purposes. The reported findings highlight the rich olive-growing heritage of this northernmost frontier of olive tree cultivation in Spain

The monumental olive trees as biocultural heritage of mediterranean landscapes: The case study of sicily

Monumental olive trees, with their longevity and their remarkable size, represent an important information source for the comprehension of the territory where they grow and the human societies that have kept them through time. Across the centuries, olive trees are the only cultivated plants that tell the story of Mediterranean landscapes. The same as stone monuments, these green monuments represent a real Mediterranean natural and cultural heritage. The aim of this paper is to discuss the value of monumental trees as “biocultural heritage” elements and the role they play in the interpretation of the historical stratification of the landscape. We present the results of a survey of the most significant olive trees growing in Sicily. The selection was based on the “monumentality” aspects of trees, taking into account dendrometric parameters and environmental contexts. The collected dataset constitutes a heterogeneous sample of 367 specimens of considerable size that, in some cases, reach a circumference of about 19 m. Starting from the data presented here, the whole Sicilian territory shows a historical relationship between human and olive. The presence of these plant monuments is, therefore, evidence of long‐term, often centennial, landscapes as a result of sustainable use of the territory

Microsatellite Markers in Olives (Olea europaea L.): Utility in the Cataloging of Germplasm, Food Authenticity and Traceability Studies

The olive fruit, a symbol of Mediterranean diets, is a rich source of antioxidants and oleic acid (55–83%). Olive genetic resources, including cultivated olives (cultivars), wild olives as well as related subspecies, are distributed widely across the Mediterranean region and other countries. Certain cultivars have a high commercial demand and economical value due to the differentiating organoleptic characteristics. This might result in economically motivated fraudulent practices and adulteration. Hence, tools to ensure the authenticity of constituent olive cultivars are crucial, and this can be achieved accurately through DNA-based methods. The present review outlines the applications of microsatellite markers, one of the most extensively used types of molecular markers in olive species, particularly referring to the use of these DNA-based markers in cataloging the vast olive germplasm, leading to identification and authentication of the cultivars. Emphasis has been given on the need to adopt a uniform platform where global molecular information pertaining to the details of available markers, cultivar-specific genotyping profiles (their synonyms or homonyms) and the comparative profiles of oil and reference leaf samples is accessible to researchers. The challenges of working with microsatellite markers and efforts underway, mainly advancements in genotyping methods which can be effectively incorporated in olive oil varietal testing, are also provided. Such efforts will pave the way for the development of more robust microsatellite marker-based olive agri-food authentication platforms

Seasonal variation of mercury concentration of ancient olive groves of Lebanon

This study investigates the seasonality of the mercury (Hg) concentration of olive tree foliage, an iconic tree of the Mediterranean basin. Hg concentrations of foliage, stems, soil surface, and litter were analyzed on a monthly basis in ancient olive trees growing in two groves in Lebanon, Bchaaleh and Kawkaba (1300 and 672 m a.s.l. respectively). A significantly lower concentration was registered in stems (∼7–9 ng g−1) in comparison to foliage (∼35–48 ng g−1) in both sites, with the highest foliage Hg concentration in late winter–early spring and the lowest in summer. It is noteworthy that olive fruits also have low Hg concentrations (∼7–11 ng g−1). The soil has the highest Hg content (∼62–129 ng g−1) likely inherited through the cumulated litter biomass (∼63–76 ng g−1). A good covariation observed between our foliage Hg time series analysis and those of atmospheric Hg concentrations available for southern Italy in the western Mediterranean basin confirms that mercury pollution can be studied through olive trees. Spring sampling is recommended if the objective is to assess the trees' susceptibility to Hg uptake. Our study draws an adequate baseline for the eastern Mediterranean and the region with similar climatic inventories on Hg vegetation uptake, in addition to being a baseline to new studies on olive trees in the Mediterranean to reconstruct regional Hg pollution concentrations in the past and present.</p