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Olive is one of the most ancient crop plants and the World Olive Germplasm Bank of Cordoba (WOGBC), Spain, is one of the world's largest collections of olive germplasm. We used 33 SSR (Simple Sequence Repeats) markers and 11 morphological characteristics of the endocarp to characterise, identify and authenticate 824 trees, representing 499 accessions from 21 countries of origin, from the WOGBC collection. The SSR markers exhibited high variability and information content. Of 332 cultivars identified in this study based on unique combinations of SSR genotypes and endocarp morphologies, 200 were authenticated by genotypic and morphological markers matches with authentic control samples. We found 130 SSR genotypes that we considered as molecular variants because they showed minimal molecular differences but the same morphological profile than 48 catalogued cultivars. We reported 15 previously described and 37 new cases of synonyms as well as 26 previously described and seven new cases of homonyms. We detected several errors in accession labelling, which may have occurred at any step during establishment of plants in the collection. Nested sets of 5, 10 and 17 SSRs were proposed to progressively and efficiently identify all of the genotypes studied here. The study provides a useful protocol for the characterisation, identification and authentication of any olive germplasm bank that has facilitated the establishment of a repository of true-to-type cultivars at the WOGBC. [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]

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]

Cultivar identification is a primary concern for olive growers, breeders, and scientists. This study was aimed at examining the SSR markers retrieved from the literature and currently used in olive study, in order to select those most effective in characterizing the olive accessions and to make possible the comparison of data obtained by different laboratories. Olive microsatellite profiles were assessed by four independent laboratories, which analyzed 37 pre-selected SSR loci on a set of 21 cultivars. These SSR markers were initially tested for their reproducibility, power of discrimination and number of amplified loci/alleles. Independent segregation was tested for each pair of SSRs in a controlled cross and the allelic error rate was quantified. Some of them were finally selected as the most informative and reliable. Most of the alleles were sequenced and their sizes were determined. Profiles of the reference cultivars and a list of alleles with their sizes obtained by sequencing are reported. Several genetic parameters have been analysed on a larger set of cultivars allowing for a deeper characterization of the selected loci. Results of this study provide a list of recommended markers and protocols for olive genotyping as well as the allelic profile of a set of reference cultivars that would be useful for the establishment of a universal database of olive accessions. [ABSTRACT FROM AUTHOR]

Thirty-two olive cultivar accessions from Syria, most of them obtained from collecting expeditions, were characterized by means of RAPD markers before being introduced in the World Germplasm Bank of Cordoba. A total of 79 polymorphic bands (6.1 polymorphisms per primer) out of 93 (7.1 bands per primer) were scored for the 13 primers used, corresponding to 84.9% of the amplification products. Thirty-one different genotypes were clearly discriminated. Differences were not found among the amplification profiles from different individuals of the same cultivar. Only two cases of mislabeling or errors of planting were found. Fourteen accessions corresponding to 6 homonyms were discriminated by RAPDs as different genotypes. The dendrogram obtained by RAPD analysis included three major groups. Some evidence of relationships of the Syrian accessions studied according to their geographic origin and/or diffusion was found. For instance, cultivars from the Central Syria (Tadmur/Palmyra) such as Toffahi', `Abbadi Abo Gabra'-1033, `Abo Kanani', `Shami'-1041, `Abbadi Shalal' `Adgam'-844 and `Majhol'-1013 clustered in Group 1 and 2. Six cultivars from Northern Syria clustered in Group 2. But it was not found a geographic structure for the cultivars from South and West of Syria. These results agree with the hypothesis of autochthonous origin of most of the olive cultivars. Some associations between cultivars from Central Syria and their fruit size were observed. This suggests that fruit size was a criterion of local selection in olive cultivars of this area. [ABSTRACT FROM AUTHOR]

RAPD markers were used for the study of 19 Albanian olive cultivars and two wild olives (oleasters). A total of 76 polymorphic bands (4.8 polymorphic markers per primer) out of 107 reproducible were obtained using 16 primers. The number of bands per primer ranged from 4 to 10, whereas the number of polymorphic bands ranged from 1 to 9, corresponding to 71% of the total amplification products. All the accessions could be identified by the combination of four primers: OPA-19; OPA-02; OPK-16 and OPP-19. The dendrogram, based on Jaccard's index, included three major groups according to their origin: 1) most of the cultivars from the area of Berat (South of Albania) 2) cultivars from the Centre and Centre-North of Albania and 3) cultivars from the Centre and North-West of Albania along with the oleaster from Elbasan. In order to evaluate the origin of Albanian cultivars they were compared to those diffused in other countries like Greece, Italy and Turkey, due to geographical and historical affinity among these countries, by using a one way AMOVA. Although most of the genetic diversity was attributable to differences among cultivars within each country (91.47%) significant φ-values among countries (φst = 0.085; p < 0.001) suggested the existence of RAPD phenotypic differentiation. Significant φ-values in all pairs formed by Albania with the other countries were observed. These results are consistent with the autochthonous origin of Albanian cultivars. [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]