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Chile has two certified origin olive products: Extra-Virgin Olive Oil (EVOO) from Huasco valley and the Azapa variety table olive from the Azapa valley. However, efficient methodologies are needed to determine the varieties and raw materials involved in the end products. In this study, we assessed the size of alleles from ten microsatellites in 20 EVOOs and in leaves and fruits of 16 olive varieties cultivated in Chile to authenticate their origins. The identification of varieties relied on specific allele sizes derived from microsatellites markers UDO99-011 and DCA18-M found in leaves and fruit mesocarp. While most Chilean single-variety EVOOs matched the variety declared on the label, inconsistencies were observed in single-variety EVOOs containing multiple varieties. Our findings confirm that microsatellites serve as a valuable as diagnostic tools for ensuring the quality control of Geographical Indication certification for Azapa olives and EVOO with Designation of Origin from Huasco.

Chile cuenta con dos productos de oliva de origen certificado: El aceite de oliva virgen extra (AOVE) del valle del Huasco y la aceituna de mesa de la variedad Azapa del valle de Azapa. Sin embargo, se necesitan metodologías eficientes para determinar las variedades y materias primas involucradas en los productos finales. En este estudio, evaluamos el tamaño de los alelos de diez microsatélites en 20 AOVEs y en hojas y frutos de 16 variedades de aceituna cultivadas en Chile para autentificar sus orígenes. La identificación de las variedades se basó en los tamaños alélicos específicos derivados de los marcadores microsatélites UDO99-011 y DCA18-M encontrados en las hojas y el mesocarpio de los frutos. Aunque la mayoría de los AOVEs chilenos monovarietales coincidían con la variedad declarada en la etiqueta, se observaron incoherencias en los AOVEs monovarietales que contenían múltiples variedades. Nuestros hallazgos confirman que los microsatélites sirven como valiosas herramientas de diagnóstico para asegurar el control de calidad de la certificación de Indicación Geográfica para aceitunas de Azapa y AOVE con Denominación de Origen de Huasco.

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Olive is one of the most important crops in the Mediterranean Basin, because of the olive oil economic value and its role in characterization of the rural landscape. The strong influence of climatic changes on the modern agriculture and the availability of a large source of genetic variability pose as crucial future challenges. Therefore, safeguarding olive genetic resources becomes fundamental, not only in cultivated forms in ex situ collections, but also in terms of wild trees in their natural habitat. In this study, 174 samples of oleaster collected in different parts of Algeria were analyzed by 16 nuclear Simple Sequence Repeats (SSRs). The analysis showed a huge genetic variability in the oleaster, and the STRUCTURE and Principal Coordinate Analyses (PCoA) highlighted clusterization of genotypes according to their geographic origin and bioclimatic conditions. Genotypes adapted to harsh climatic conditions were identified, which could be useful to enrich the panel of olive genotypes for breeding purposes and preserve genetic diversity of this species from erosion risks.(AU)

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Stearoyl-ACP desaturases (SADs) and fatty acid desaturases (FADs) play a critical role in plant lipid metabolism and also affect oil fatty acid composition introducing double bonds into the hydrocarbon chains to produce unsaturated fatty acids. In the present study, the genomic sequences of three SAD and three FAD candidate genes were characterized in olive and their expression was evaluated in different plant tissues. OeSAD genes corresponded to olive SAD1 and SAD2 and to a newly identified OeSAD4, sharing the conserved protein structure with other plant species. On the other hand, the full-length genomic sequences of two microsomal OeFAD genes (FAD2-1 and FAD2-2) and the plastidial FAD6, were released. When the level of expression was tested on different tissues of cv. Leccino, OeSAD1 and OeSAD2 were mainly expressed in the fruits, while OeFAD genes showed the lowest expression in this tissue. The mRNA profiling of all genes was directly studied in fruits of Leccino and Coratina cultivars during fruit development. In both genotypes, the expression level of OeSAD1 and OeSAD2 had the highest value during and after the pit-hardening period, when oil accumulation in fruit mesocarp is intensively increasing. Furthermore, the expression level of both OeFAD2 genes, which were the main candidates for oleic acid desaturation, were almost negligible during fruit ripening. These results have made possible to define candidate genes of the machinery regulation of fatty acid composition in olive oil, providing information on their sequence, gene structure and chromosomal location.

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Olive is a long-living perennial species with a wide geographical distribution, showing a large genetic and phenotypic variation in its growing area. There is an urgent need to uncover how olive phenotypic traits and plasticity can change regardless of the genetic background. A two-year study was conducted, based on the analysis of fruit and oil traits of 113 cultivars from five germplasm collections established in Mediterranean Basin countries and Argentina. Fruit and oil traits plasticity, broad-sense heritability and genotype by environment interaction were estimated. From variance and heritability analyses, it was shown that fruit fresh weight was mainly under genetic control, whereas oleic/(palmitic + linoleic) acids ratio was regulated by the environment and genotype by environment interaction had the major effect on oil content. Among the studied cultivars, different level of stability was observed, which allowed ranking the cultivars based on their plasticity for oil traits. High thermal amplitude, the difference of low and high year values of temperature, negatively affected the oil content and the oleic acid percentage. Information derived from this work will help to direct the selection of cultivars with the highest global fitness averaged over the environments rather than the highest fitness in each environment separately.

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The olive (Olea europaea L.) is a leading oil crop in the Mediterranean area. Limited information on the inheritance of agronomic significant traits hinders progress in olive breeding programs, which encourages the development of markers linked to the traits. In this study, we report on the development of 46 olive simple sequence repeat (SSR) markers, obtained from 577,025 expressed sequence tags (ESTs) in developing olive fruits generated in the framework of the Slovenian national olive transcriptome project. Sequences were de novo assembled into 98,924 unigenes, which were then used as a source for microsatellites searching. We identified 923 unigenes that contained 984 SSRs among which dinucleotide SSRs (36 %) were the most abundant, followed by tri- (33 %) and hexa- (21 %) nucleotides. Microsatellite repeat motif GA (37 %) was the most common among dinucleotides, while microsatellite repeat motif GAA was the most abundant trinucleotide SSR motif (16 %). Gene ontology annotations could be assigned to 27 % of the unigenes. A hundred and ten expressed sequence tag-derived-simple sequence repeats (EST-SSRs) with annotated genes were selected for primer designing and finally, 46 (42 %) polymorphic EST-SSRs were successfully amplified and used to validate genetic diversity among 24 olive varieties. The average number of alleles per locus, observed heterozygosity, expected heterozygosity, and polymorphic information content were 4.5, 0.649, 0.604 and 0.539, respectively. Twenty-seven EST-SSRs showed good diversity properties and were recommended for further olive genome investigation.

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RESUMO

The olive (Olea europaea L.) is a leading oil crop in the Mediterranean area. Limited information on the inheritance of agronomic significant traits hinders progress in olive breeding programs, which encourages the development of markers linked to the traits. In this study, we report on the development of 46 olive simple sequence repeat (SSR) markers, obtained from 577,025 expressed sequence tags (ESTs) in developing olive fruits generated in the framework of the Slovenian national olive transcriptome project. Sequences were de novo assembled into 98,924 unigenes, which were then used as a source for microsatellites searching. We identified 923 unigenes that contained 984 SSRs among which dinucleotide SSRs (36 %) were the most abundant, followed by tri- (33 %) and hexa- (21 %) nucleotides. Microsatellite repeat motif GA (37 %) was the most common among dinucleotides, while microsatellite repeat motif GAA was the most abundant trinucleotide SSR motif (16 %). Gene ontology annotations could be assigned to 27 % of the unigenes. A hundred and ten expressed sequence tag-derived-simple sequence repeats (EST-SSRs) with annotated genes were selected for primer designing and finally, 46 (42 %) polymorphic EST-SSRs were successfully amplified and used to validate genetic diversity among 24 olive varieties. The average number of alleles per locus, observed heterozygosity, expected heterozygosity, and polymorphic information content were 4.5, 0.649, 0.604 and 0.539, respectively. Twenty-seven EST-SSRs showed good diversity properties and were recommended for further olive genome investigation.(AU)

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The olive tree is an iconic tree of the Mediterranean, and is used extensively to produce high-quality olive oil. Although the China olive industry has just begun to be valued, there were also existed mislabeling and synonyms in introduced cultivars. The aim of this study was to analyze genetic similarities among olive cultivars in China using SSR and ISSR techniques. Thirty-two samples were collected from Xichang. Five of these cultivars were issued from a Chinese breeding program. Genomic DNA samples were extracted from young leaves and PCR was used to generate SSR and ISSR markers. A total of 107 polymorphic bands were detected on thirteen SSR loci, with an average of eight alleles per locus. The observed heterozygosity ranged from 0.785 (DCA03) to 0.990 (GAPU47), and the expected heterozygosity varied between 0.782 (DCA03) and 0.940 (GAPU103A). The discrimination power ranged from 0.57 to 0.83, while the polymorphism information content values ranged from 0.768 (DCA03) to 0.934 (GAPU103A). Nine ISSR primers generated 85 reproducible bands of which 78 (91.8%) were polymorphic. Based on our data, genetic similarity between cultivars ranged from 0.57 to 0.83. Cluster analysis revealed that 32 cultivars were clustered into six groups, which supports similar morphology such as use, oil content and fruit weight but not similar geographical origins. Our data also allow the identification of unknown cultivars and cases of synonyms.

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The purpose of this research was to characterize an olive core collection using some agronomic characters and simple sequence repeat (SSR) markers and to determine SSR markers associated with the content of fatty acids in olive oil. SSR marker analysis demonstrated the presence of a high amount of genetic variation between the olive cultivars analyzed. A UPGMA dendrogram demonstrated that olive cultivars did not cluster on the basis of their geographic origin. Fatty acid components of olive oil in these cultivars were determined. The results also showed that there was a great amount of variation between the olive cultivars in terms of fatty acid composition. For example, oleic acid content ranged from 57.76 to 76.9% with standard deviation of 5.10%. Significant correlations between fatty acids of olive oil were observed. For instance, a very high negative correlation (-0.812) between oleic and linoleic acids was detected. A structured association analysis between the content of fatty acids in olive oil and SSR markers was performed. STRUCTURE analysis assigned olive cultivars to two gene pools (K = 2). Assignment of olive cultivars to these gene pools was not based on geographical origin. Association between fatty acid traits and SSR markers was evaluated using the general linear model of TASSEL. Significant associations were determined between five SSR markers and stearic, oleic, linoleic, and linolenic acids of olive oil. Very high associations (P < 0.001) between ssrOeUA-DCA14 and stearic acid and between GAPU71B and oleic acid indicated that these markers could be used for marker-assisted selection in olive.

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The purpose of this study was to characterize olive core collection with amplified fragment length polymorphism (AFLP) markers and fruit traits and to determine AFLP markers significantly associated with these fruit characters in olive. A total of 168 polymorphic AFLP markers generated by five primer combinations and nine fruit traits were used to characterize relationships between 18 olive cultivars. Although all olive cultivars were discriminated from each other by either AFLP markers (<0.75 similarity level) or fruit traits, clustering based on the AFLP markers and fruit traits was not significantly correlated (r = 0.13). Partial clustering of olive cultivars by AFLP markers according to their geographical origin was observed. Associations of AFLP markers with fruits were determined using a multiple-regression analysis with stepwise addition of AFLP markers. Significant associations between eight AFLP markers and fruit traits were identified. While five AFLP markers demonstrated significant negative correlation with fruit and stone weight, width and length and total polyphenols (P < 0.05), three AFLP markers displayed significant positive correlation with α-tocopherol and γ-tocopherol (P < 0.01). This is the first report on the association of molecular markers with fruit traits in olive. Molecular markers associated with morphological and agronomic traits could be utilized for the breeding of olive cultivars. However, the association power of these markers needs to be confirmed in larger populations, and highly correlated markers should then be converted to PCR-based DNA markers such as sequence-characterized amplified region markers for better utilization.

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Olive (Olea europaea L.) shows alternate bearing, with unreliable cropping patterns and inconsistent fruit size and quality every year. In many countries, thinning with naphthaleneacetic acid (NAA) is used to minimise alternate bearing behavior in olives. However, in Italy, growers are reluctant to employ this practice and no detailed knowledge is available for specific cultivars. We evaluated the effects of spraying NAA on various dates on the productive and vegetative characteristics of the main Italian table olive cultivar'Nocellara del Belice'. Trunk cross-sectional area, fruit set, fruit drop, fruit size, pit size, yield per tree, crop density and flesh to pit ratio were analysed. The NAA treatment applied on the earliest of the dates selected increased fruit weight and flesh to pit ratio, by reducing crop density and enhancing the leaf to fruit ratio, without reducing yield. Two distinct negative relationships were found between fruit weight and crop density during "on" and "off" years, but a unique relationship between pit weight vs. crop density in both years, suggested that the pit is the strongest sink. Fruit size and quality of'Nocellara del Belice' can be enhanced by NAA application, thereby increasing economic returns in the "on" year.(AU)

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