Olive Germplasm – Italian Catalogue of Olive Varieties
 Agricultural Research Council – Olive Growing and Oil Industry Research Centre, Rende (CS), Italy
It is of great importance to evaluate and characterize the existing genetic diversity of the crop species, mainly for those, such as the case of olive, which still have a well preserved great cultivar patrimony, in spite of the disturbance of the environments where they are cultivated. This issue is of particular importance in areas where a number of varieties show adaptation to the difficult local environmental conditions.
The genetic patrimony of the Mediterranean Basin’s olive trees are very rich and is characterised by an abundance of varieties. Based on estimates by the FAO Plant Production and Protection Division Olive Germplasm (FAO, 2010), the world’s olive germplasm contains more than 2.629 different varieties, with many local varieties and ecotypes contributing to this richness.
The problem of olive germplasm classification is not only complicated by the richness of its genetic patrimony, but also by the absence of reference standards and by the confusion regarding the cultivar names, with numerous cases of homonymy (one denomination for several genotypes) and synonymy (one genotype with several denominations).
The Italian olive germplasm is estimated to include about 800 cultivars, most of them landraces vegetatively propagated at a farm level since ancient times. The number is probably underestimated because of the scarce information on minor local varieties widespread in the different olive growing areas. The study of these less-common cultivars is important because they may have traits not considered important in the past but necessary to meet the challenges of modern olive growing. Low vigour, resistance to low temperatures, salinity tolerance, adaptability to low pruning systems, late ripening and fatty-acid content are important traits for olive or olive oil quality. Additionally, morphological characters are sometime correlated or associated with disease susceptibility and can be used as markers in breeding.
The largest olive collection (accounting for 17 percent of the total olive trees with more than 500 varieties) is held by Agricultural Research Council – Olive growing and oil industry research centre (CRA-OLI) in Italy, followed by the collections of the Centro de Investigación y FormaciónAgroalimentaria Córdoba (CIFACOR) in Spain. The systematic collection of Italian olive varieties for deposit into specific catalogue fields began in Italy in the 1980s. A similar international collection was begun in 1997 by CRA-OLI of Rende, Italy. Collection entailed the following steps: a survey of the territory, individuation, basic characterization, and introduction into the gene bank field. Material identified by other international scientific institutions (International Treaty on Plant Genetic Resources for Food and Agriculture – Plant Genetic Resources RGV-FAO Projects) was also included. To date, roughly 500 varieties have been introduced into the CRA-OLI collection, and this list has been published (web site http://apps3.fao.org/wiews/olive/oliv.jsp). The goal of such collections is to safeguard all cultivars, and particularly the minor ones, to avoid a loss in genetic diversity and to offer an interesting genetic basis for breeding programs. Knowledge of genetic diversity in a crop species is fundamental to its improvement. A variety of molecular, chemical and morphological descriptors are used to characterize the genetic diversity among and within crop species.
Morphological and biological characters have been widely used for descriptive purposes and are commonly used to distinguish olive cultivars. Agronomic characterization also allowed the classification of different olive cultivars. Different molecular markers have recently been used to characterize and distinguish the olive cultivars.
Management of the CRA-OLI collection includes a description of its genetic diversity for a reliable characterization of all accessions since several cases of mislabelling, homonymy and synonymy could exist.
In the present work, we used morphological characterization and molecular markers and to characterize all accessions present in the CRA-OLI collection, to build a first molecular and morphological data-base and to analyze the genetic relationships between cultivars.
We used SSR markers for genotyping the complete collection of the olive germplasm. The experimental approach was based on using the parameters as recommended by International Olive Council (COI) for characterization and the bio-agronomic observations concerned the morphological characteristic of the trees, leaves, fruit and inflorescence and the flowering period. The fruits were examined for their morphology and oil composition and for endocarp characteristics.
Over 200elaiographic cards with colour photos, graphs and tables and with full details relating to the identification the olive varieties growing in the CRA-OLI olive germplasm collection in Calabria, Italy were reported in annex. Additional information about agronomic behaviour of the plants, and the organoleptic oil values, as determined by a panel test, were also recorded.