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Dormancy release dynamics in olive tree (Olea europaea L.) reproductive buds as affected by cold accumulation, tree bearing status, and budburst temperature was studied under natural and controlled conditions, using both cuttings and container- and field-grown plants. The chilling necessary for dormancy release was acquired at different times within the bud population, presenting a progressive pattern of reproductive budburst. Once sufficient chilling is accumulated, 20 °C is a suitable temperature for reproductive budburst, although higher temperature, e.g., 30 °C, during dormancy release can inhibit budburst. While the bearing status of trees determined the amount of return bloom, dormancy release followed a similar pattern for previously bearing and non-bearing trees. Concurrent with investigating budburst factors, the use of shoot cuttings was tested as a method for olive dormancy release studies by contrasting with results from whole trees. It was found it to be valid for studying reproductive budburst, thus providing a useful method to screen chilling requirements in cultivar evaluation and the breeding programs currently ongoing in this species. However, the method was not valid for vegetative budburst, with varying results between cuttings and the whole plant. [ABSTRACT FROM AUTHOR]

More than 11 million ha of olives ( Olea europaea L.) are currently grown worldwide, 98% of which are localized in the Mediterranean Basin, with olives being one of the most important fruit trees in the area. The olive fruit is a very particular drupe since it not may be directly consumed but must instead be processed. Table olives and virgin olive oil are the two main processed products derived from olive fruits. Both are considered staple foods of the Mediterranean Diet and have been produced in the area for centuries, presumably since olive domestication occurred approximately 6.000 years ago. Despite their long history and economic importance, the focus on quality is quite recent. The presence of various and copious amounts of bioactive compounds, some of which are exclusive to olives, is drawing attention to the nutraceutical value of these products. This review aims to integrate the available information regarding the quality of table olives and olive oil with a focus on how preharvest factors may affect quality. The first part of the review describes the main quality attributes considered for each product from different perspectives, including the legal, organoleptic and nutritional points of view, among others. The physiological mechanisms involved in fruit development and ripening, which significantly affect the quality of the fruits, i.e., the raw material for obtaining both products, are also discussed. The review also addresses the potential of both the considerable number of traditional olive cultivars and recent olive breeding programs to obtain products with distinct quality attributes (in terms of sensorial profile and bioactive compounds). Finally, the most recent literature concerning the effect of environmental (soil and climate) and agronomical factors (irrigation, fertilization, canopy management and harvesting) is extensively reviewed. [ABSTRACT FROM AUTHOR]

Super high-density (SHD) olive orchards are rapidly expanding since the first plantation was set up in Spain in the 1990s. Because there are no long-term studies characterizing these systems, it is unknown if densities above a certain threshold could trigger competition among fully-grown trees, compromising their development. Over 14 years we have evaluated the performance of the major olive cultivars currently planted in SHD systems ("Arbequina," Arbequina IRTA-i.18, "Arbosana," "Fs-17," and "Koroneiki") and nine SHD designs ranging from 780 to 2254 trees ha-1 for the cultivar "Arbequina." Remarkably, the accumulated fruit and oil production of the five cultivars increased linearly over time. Our data indicated the favorable long-term performance of the evaluated cultivars with an average annual oil production of 2.3 t ha-1. Only "Fs-17" did not perform well to the SHD system in our conditions and it yielded about half (1.2 t ha-1) of the other cultivars. In the density trial for "Arbequina," both fruit and oil accumulated production increased over time as a function of tree density. Thus, the accumulated oil yield ranged from 16.1 t ha-1 for the lowest density (780 trees ha-1) to 29.9 t ha-1 for the highest (2254 trees ha-1). In addition, we note that the accumulated production per surface unit showed a better correlation with the hedgerow length than the tree density. Thus, the current planting designs of SHD olive orchards can be further improved taking this parameter into account. Despite observations that some irregular patterns of crop distribution have arisen, our olive hedgerows are still fully productive after 14 years of planting. This result contradicts previous experiences that showed declines in production 7 or 8 years after planting due to high vigor, shading, and limited ventilation. [ABSTRACT FROM AUTHOR]

Olive ( Olea europaea ssp. europaea) is the most important oil fruit crop in temperate areas, but the origin of the cultivated olive remains unclear. The existence of one or several domestication events in the Mediterranean Basin ( MB) is still debated., We analyzed a dataset of 387 cultivated and wild accessions that were genotyped at 25 simple-sequence repeat ( SSR) loci. The sample represented genetic diversity at the geographic extremes of the MB. We inferred relationships among samples and also applied approximate Bayesian computation to estimate the most probable demographic model of our samples., Cultivated olives clustered into three different gene pools (Q1, Q2 and Q3), corresponding loosely to the west, central and eastern MB, respectively. Q1 consisted primarily of accessions from southern Spain, retained the fingerprint of a genetic bottleneck, and was closely related to accessions from the eastern MB. Q2 showed signs of recent admixture with wild olives and may derive from a local domestication event in the central MB., Overall our results suggest that admixture shaped olive germplasm and perhaps also local domestication events. [ABSTRACT FROM AUTHOR]

Narrow hedgerows system (NHS) is a new concept of olive orchards characterized by minimum labor requirements, continuous mechanical harvesting, early bearing, high yield, and olive oil quality. In this work, the variability of phenolic composition of virgin olive oils (VOOs) was studied in three cultivars (Arbequina, Arbosana, and Sikitita), two planting systems (NHS: 1975 trees/ha and intensive system (IS): 333 trees/ha) and different harvesting dates (1 October and 26 November for the three cultivars; and three additional dates for the new olive Sikitita: 16 and 29 October; and 12 November). Phenolic compounds were extracted from the obtained VOOs by liquid-liquid extraction with 60:40 v/v methanol/water. The resulting hydroalcoholic extract was analyzed by liquid chromatography - diode-array detector - fluorescence detection (LC-DAD-FD) for individual phenols separation-quantification. Significant differences among genotypes were found for some individual phenols at the first harvesting date. At the second harvesting date, significant differences were found between genotypes and between planting systems ( p<0.05). According to the obtained results, the new Sikitita should be harvested at the beginning of the ripening period for obtaining VOO with high phenolic content. Finally, a global agronomic and oil compositional evaluation in NHS of the new cultivars bred specifically is needed for this new olive growing system. Practical applications: Narrow hedgerow is a new very high density (>1500 trees/ha) olive planting system associated to overhead vineyard harvesters that is increasingly used as it reduces drastically both labor and time needed to harvest the crop. This study focuses on the comparison of the content of phenolic compounds in olive oils originated from narrow hedgerow system and intensive system. The results can be used to determine the best time for harvesting the new olive Sikitita, recently selected for narrow hedgerow system, in order to obtain an olive oil with high phenolic content. [ABSTRACT FROM AUTHOR]

BACKGROUND: The progressive transformation of olive growing and the increasing demands for high-quality monovarietal virgin olive oil (VOO) have triggered interest in olive breeding programs, in which the evaluation of the new genotypes is the basis for obtaining new olive cultivars. In this work, the phenolic composition of VOOs from two progenies from crosses between 'Arbequina', 'Arbosana' and 'Sikitita' has been evaluated along two years. RESULTS: A higher degree of variation was observed in segregating population as compared to genitors. The results also showed that the variability within crosses constitutes the major contribution to total variance for all considered parameters (>92% of total sum of squares). All compounds under study were present in oils obtained in both years; however, clear differences in their concentrations were observed between years. CONCLUSION: Olive breeding can indeed provide genotypes that produce oils with improved phenolic profiles as compared to traditional cultivars. In addition, the data showed that selection as a function of tyrosol content could be achieved in only one crop year. Finally, p-coumaric acid was the unique component able to discriminate between both crop years under study. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The evaluation and characterization of segregating populations is a critical step in olive breeding programs. In this work, phenolic profiles of virgin olive oils (VOOs) from segregating populations obtained by cross breeding in Cordoba (Spain) have been evaluated. Genotypes obtained from open pollination of the cultivar Manzanilla de Sevilla, and from crosses between the cultivars Arbequina × Arbosana, Picual × Koroneiki and Sikitita × Arbosana were tested. The phenolic composition was determined after liquid-liquid extraction with 60:40 v/v methanol-water and subsequent chromatographic analysis with ultraviolet (UV) detection of both absorption and fluorescence in a sequential configuration. Results for all studied compounds showed high degree of variability between genotypes, with a higher range of variation than the observed for the genitors. Most of the observed variability was attributable to differences in genotypes within crosses rather than among crosses. Some issues related to breeding strategies are discussed. Practical applications: Phenolic compounds are considered to be of paramount importance for the assessment of virgin olive oil quality due to their contribution to the nutraceutical and sensory profile of this natural food. This study focuses on the evaluation of the content of phenolic compounds in olive oils originated from cross breeding in an olive breeding program (Cordoba, Spain). This step is crucial to determine the range of variation of phenolic compounds and the selection of interesting genotypes with higher composition in total phenols or in an individual phenol targeted at a breeding program. [ABSTRACT FROM AUTHOR]

Core collections reflecting the diversity of large germplasm collections are valuable tools to conserve and evaluate the genetic resources more effectively. Three strategies using two different search algorithms were trained to develop the most representative nested core collection of the World Olive Germplasm Bank (WOGB) of Cordoba (Spain), the largest and best characterized collection of olive (Olea europaea L.) cultivars worldwide. The original dataset was composed of 378 olive accessions from 21 different countries characterized by 14 microsatellite markers (simple sequence repeats [SSRs]). Each nested core collection included five subsets representing different percentages of the base collection (5, 10, 15, 20, and 30%). The strategy maximizing the allele coverage implemented in the software Core Hunter was chosen as the best. The five subsets developed by this method captured the maximum number of alleles showing fewer significant differences in their frequencies with respect to the whole collection. Additionally, a balanced geographical composition was observed in the nested subsets in spite of the strong overrepresentation of western Mediterranean accessions present in the WOGB. The results of this study are aimed at improving both the conservation and management of olive genetic resources and the study of differential genotype × environment interactions by testing a minimum number of accessions. [ABSTRACT FROM AUTHOR]

The duration of the juvenile period (JP) before the seedlings reach the adult phase (AP) and begin flowering is the major impediment for fruit breeding in olive. In this work, the effect of soil solarization on the growth and duration of the JP of olive seedlings was studied. Seedlings obtained from open pollination of 'Manzanilla de Sevilla' and from crosses between 'Arbequina' x 'Arbosana' and 'Picuar x 'Koroneiki' were tested. Solarization treatment consisted on covering the soil around the trees for 3 years by black plastic film in a split-plot design with the three progenies as the main factor and solarization/not solarization as the secondary factor. Solarization resulted in both higher soil temperature and soil moisture in solarized plots with respect to non-solarized. Significant differences between crosses were found for plant vigor and flowering measurements throughout the experiment. Soil solarization increased trunk diameter and the number of seedlings reaching AP in 'Manzanilla' open progeny. A positive effect of solarization on flowering index was also observed in 'Picuar x 'Koroneiki' progenies. These results suggest that soil solarization may be recommended as a tool for shortening the duration of the JP and thus accelerating the selection process in olive breeding programs. [ABSTRACT FROM AUTHOR]

Virgin olive oil (VOO) consumption is increasing all over the world due to its excellent organoleptic and nutraceutical properties. These beneficial traits stand from a prominent and well-balanced chemical composition, which is a blend of major (98% of total oil weight) and minor compounds including antioxidants. The main antioxidants are phenolic compounds, which can be divided into lipophilic and hydrophilic phenols. While lipophilic phenols such as tocopherols can be found in other vegetable oils, most hydrophilic phenols in olive oil are exclusive of the Olea europaea species endowing it with a chemotaxonomic interest. This review is focused on VOO antioxidant profile and, particularly, on hydrophilic phenols that are divided into different sub-families such as phenolic acids and alcohols, hydroxy-isochromans, flavonoids, secoiridoids, lignans and pigments. Analytical methods for qualitative and/or quantitative determination of these compounds are assessed. The implementation of efficient sample preparation protocols, separation techniques such as liquid chromatography, GC and capillary electrophoresis, as well as detection techniques such as ultraviolet absorption, fluorescence or MS are critical to succeed in the quality of the results. The effects of hydrophilic phenols on increasing VOO stability, its nutraceutical interest and organoleptic properties are also considered. [ABSTRACT FROM AUTHOR]

The biosynthesis of the phenolic fraction of olive fruits during ripening and the transformations occurring in this moiety during virgin olive oil (VOO) extraction are discussed in this paper. The influence of agronomical factors that can significantly affect the phenolic profile of VOO is also discussed. Particularly, it is worth emphasizing the role of genetic factors, cultivation and climatic conditions such as water availability, atmospheric temperature, altitude, health status of the fruits, alternate bearing in the olive, and some processing factors such as crushing, malaxation time and temperature or volume of water added during milling. Among these parameters, special attention has been paid to genetic factors due to the high variability observed among Olea europaea genotypes for all recorded traits. In this context, interesting experimental results have been obtained with cultivated and wild olive trees, and also with segregating populations resulting from olive breeding programs. To the authors' knowledge, reviews evaluating the influence of the main factors that contribute to the profile of hydrophilic phenols have not been previously published. The discussion concerning olive breeding programs is a major and novel aspect to be emphasized considering recent trends to obtain new olive cultivars that confer better organoleptic properties and better quality to VOO. [ABSTRACT FROM AUTHOR]

The article provides information on the Chiquitita olive cultivar obtained in a crossbreeding program in Cordoba, Spain. The origin of Chiquitita seedling was a cross between the Picual and Arbequina varieties. Based on a comparative field trial plot established in 2001, Chiquitita has lower vigor than Arbequina and the former's height failed to reach the more than 3 m height in the third season of the latter. Also discussed are the fruit and oil characteristics of the olive cultivar.

Highlights: [•] Effective methods to screen massively olive genotypes for Verticillium wilt resistance are needed. [•] We tested three different inoculation methods. [•] For the best inoculation method, we tested the influence of the environment and the age of the plants. [•] Root-dipping inoculation of young olive seedlings and evaluation under growth chamber conditions is an effective method to screen for resistant genotypes. [•] This screening method is suitable as a first step in a breeding program for Verticillium wilt resistance in olive. [ABSTRACT FROM AUTHOR]

Numerous olive cultivars are cultivated in Iran, mainly in the north. Ninety-two accessions belonging to 10 main olive cultivars were screened by 13 microsatellite markers revealing high genetic variability both within and between cultivars. In total, 72 alleles were detected with a mean number of 5.5 alleles per locus. Twenty-four unique allelic patterns were observed, whereas six genotypes showed 15 unique alleles. Heterozygosity ranged from 0.00 to 0.98, whereas the mean number of discrimination power and polymorphic information content were 0.55 and 0.54, respectively. The combination of 5 simple sequence repeat markers made discrimination of 84% of all accessions included in the study possible. The existence of homonyms, synonyms, or mislabeling as well as intracultivar polymorphism was revealed by allele differences between accessions of the same denomination. The phenogram showed variability among as well as between some cultivars, but most accessions with the same generic names were grouped together. [ABSTRACT FROM AUTHOR]

The initial results of a comparative field trial of the first 15 selections of the olive (Olea europaea L.) breeding program of Cordoba, Spain, are presented. These selections came from crosses among 'Arbequina', 'Frantoio', and 'Picual' that were also included in the trial as controls. The trial was planted in July 2001 in a randomized block design with 16 replications and was systematically evaluated for earliness of bearing, vigor, crop, and yield efficiency from 2001 to 2005. Significant differences among selections were found for all characters measured. A greater proportion of early-bearing genotypes than in previous cultivar collections were found, whereas mean accumulated yield was similar to former evaluations. Therefore, the shorter unproductive period obtained in this work seems to indicate that the selection of seedlings for a short juvenile period has provided a shorter unproductive period of the subsequent new cultivars. No correlation between vigor at the seedling stage and vigor in the corresponding adult vegetative propagated selection was found, if the data presented here are confirmed further, some early-bearing cultivars could be suggested as new olive cultivars, the first obtained by cross-breeding in Spain. Additionally, some of them also show a low vigor and could be adapted to high-density hedgerow orchards. [ABSTRACT FROM AUTHOR]

A first attempt to determine the effect of vigor and parents on the length of the juvenile period of olive seedlings is here reported. Vigor seems to have a significant influence on the percentage of flowering seedlings, especially in the first 2 years of bearing. The different parents used have produced differences in the juvenile period of their descendants. A correspondence between the length of the unproductive period of the parents and the length of the juvenile period that they transmit to their descendants has been observed. The seedling forcing growth protocol described here has been able to produce flowering seedlings 28 months after germination, with >93% of seedlings flowering 65 months after germination. [ABSTRACT FROM AUTHOR]

We have determined delta(13)C, delta(2)H and delta(18)O isotopic abundances in Andalusian olive oils. In addition, the fatty acid composition and the distribution of isomers at positions 1,3 and 2 of glycerol were determined by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy, respectively. Isotopic results obtained for four series of oil samples extracted from olives harvested in the 2004/05 and 2005/06 seasons are discussed in terms of olive variety, ripeness, geographical origin, fatty acid composition and growing altitude. A distinction was also established between olives grown in irrigated and in dry land by studying selected samples of the previous series and others from the 2005/06, 2006/07, 2007/08 and 2008/09 seasons. The results showed that olive ripeness does not influence the abundance of any of the three isotopes studied. On the other hand, the olive variety influences the abundance of the oxygen and hydrogen isotopes, and also, less markedly, that of carbon. No clear-cut effect of height or latitude on isotope values is observed, probably because the olive variety also changes with height and latitude, thus masking such influences. The oil samples from dryland-grown olives had increased delta(13)C values relative to irrigation-grown olives. In addition, no definite relationship appears to exist between isotope distribution and fatty acid composition. Finally, oil samples from olives harvested in the 2005/06 season in Italy could be distinguished from those from Spain in terms of their isotopic values (delta(2)H mainly)., (Copyright 2010 John Wiley & Sons, Ltd.)