The cultivar Oblonga may have originated from a volunteer seedling at an orchard near Corning, Calif., about 1940. Its main virtue is its high degree of resistance to Verticillium dahliae. `Frantoio' is the main variety in Italy and has been planted worldwide because of its high content of top-quality oil. In the present study, we show that both cultivars have the same fifteen morphological and eight agronomical traits and both have amplified the same patterns for 22 RAPD primers and five SSRs. This indicates that `Oblonga' and `Frantoio' are probably the same cultivar.
Diego Barranco, Isabel Trujillo and Pilar Rallo
Isabel Trujillo, Luis Rallo and Pere Arús
Pollen samples of 155 olive (Olea europaea L.) cultivars from different origins were analyzed to study isoenzymatic variability in five enzyme systems: alcohol dehydrogenase (ADH), esterase (EST), glucose phosphate isomerase (GPI), leucine aminopeptidase (LAP), and malic enzyme (ME) using starch gel electrophoresis. Polymorphism was observed in all of the isozyme systems. ME, GPI, EST, and LAP were the most useful systems for identification of cultivars. Different combinations of banding patterns of these systems allowed us to identify 85% of the cultivars. The remainder were separated into groups of two or three cultivars that could be identified using morphological characteristics. No intracultivar polymorphisms were observed.
Maria G. Emmanouilidou, Marios C. Kyriacou and Isabel Trujillo
Implementation of the recently developed Cyprus National Register of Commercial Varieties mandates proper cataloguing of the material conserved in the ex situ Olive Collection at the Agricultural Research Institute of Cyprus. A total of 125 trees belonging to 32 accessions were analyzed using 11 morphological endocarp traits and 14 microsatellite [simple sequence repeat (SSR)] markers. The SSR variability allowed segregation of 16 genotypes among accessions, which were clustered into three main groups based on genetic similarity. Similarity indexes among groups ranged from 0.63 to 0.65 and within groups were ≥0.9. Lower morphological variability was detected among accessions, which conformed to three morphological profiles; moreover, the three morphological profiles corresponded to the three groups of genetic similarity obtained by SSR markers. The identification, based on the unique combination of SSR genotypes and endocarp morphologies, revealed the presence of three cultivars and 15 molecular variants that presented limited molecular differences but morphological profiles identical to their catalogued cultivars. Two cultivars, ‘Ladoelia’ and ‘Kato Drys’, demonstrated molecular variation. The current study underpins the efficient management of olive germplasm collections based on combined molecular and phenotypic characterization of their accessions. The complete cataloguing of olive germplasm ensures the correct distribution of identified and authenticated material across national or international institutions.
Mahdi Fendri, Isabel Trujillo, Ahmed Trigui, María Isabel Rodríguez-García and Juan de Dios Alché Ramírez
Most traditional olive-producing countries possess a diversified genetic patrimony in Olea europaea L. Since the emergence of modern olive growing system, the identification, classification, and conservation of autochthonous olive cultivars is a priority for these countries. In this work, a total of 84 accessions belonging to the “Boughrara”-Sfax olive germplasm collection located in Tunisia have been screened using a powerful set of eight simple sequence repeat markers (SSRs). The study revealed a high genetic variability among the collection and detected a total of 64 alleles. For better management of the mentioned germplasm bank, an improved classification of the entries, including new denominations, has been proposed. In addition, several cases of mislabeling, synonymy, and homonymy have been clarified. Genetic relationships among cultivars have been analyzed showing four major clusters. Finally, a correspondence factor analysis demonstrated that cultivars tend to cluster depending on their main use as oil or table olives. No clear clustering tendencies were observed when the geographical origin of cultivars was used as the criteria for the analysis. All results obtained by SSR screening and classification were in accordance with classification based on morphological traits of fruit endocarps.
Zahra Noormohammadi, Mehdi Hosseini-Mazinani, Isabel Trujillo, Luis Rallo, Angjelina Belaj and Majid Sadeghizadeh
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.
Fernando Santos-Antunes, Lorenzo León, Raúl de la Rosa, Juán Alvarado, Ana Mohedo, Isabel Trujillo and Luis Rallo
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.