Hazelnut (Corylus avellana L.) is a traditional nut crop in southern Europe. Germplasm exploration conducted on-farm in five countries (Portugal, Spain, Italy, Slovenia, and Greece) identified 77 landraces. The present work describes phenotypic variation in nut and husk traits and investigates genetic relationships using ten simple sequence repeat (SSR) markers among these landraces, 57 well-known references cultivars, and 19 wild accessions. Among the 77 landraces, 42 had unique fingerprints while 35 showed a SSR profile identical to a known cultivar. Among the 42 unique landraces, morphological observations revealed high phenotypic diversity, and some had characteristics appreciated by\ud the market such as nut round and caliber. Analysis of genetic relationships and population structure allowed investigation of the origin and spread of the cultivated germplasm in southern Europe. Our results indicate the existence of three primary centers of diversity in the Mediterranean basin: northwestern Spain (Tarragona) and southern Italy (Campania) in the West and Black Sea (Turkey) in the East. Moreover, the data suggest the existence of secondary gene pools in the Iberian (Asturias) and Italian (Liguria and Latium) Peninsulas, where\ud local varieties were recently domesticated from wild forms and/or from introduced ancient domesticated varieties

In the frame of SAFENUT AGRI GEN RES Action, which was a European strategy for the recovery, characterization and conservation of genetic resources, the fatty acids and the tocopherol profiles of a set of 75 hazelnut accessions were analyzed. The aim of this study was to assess the genetic differences among the European germplasm, contributing to the definition of nut quality in traditional European areas of cultivation. Significant differences were found between accessions for oil amount and contents of most fatty acids. As expected, monounsaturated fatty acids made up the largest portion (mean 80.85 %) followed by polyunsaturated fatty acids (10.70 %). The saturated ones were the minor components and accounted for only 8.43 % of the total fatty acids. On the basis of Student's test, significant differences between the 2 years of harvest were found for fatty acid content, except for linoleic acid, the ratio of polyunsaturated, a-tocopherol and the stability index. When the oil content was studied in cultivars from the same site of cultivation, the mean values of the genetic pools from central Italy (60.8 %), Slovenia (59.3 %) and Portugal (58.2 %) showed highest values than those of cultivars grown in Greece (56.8 %), Spain (55.9 %) and France (51.5 %). A chemometric approach based on principal component and clustering analyses was developed to identify the most interesting cultivars for breeding programs.

During recent years, there has been increasing awareness of the importance of adopting a holistic view of biodiversity, including agricultural biodiversity, conservation for sustainable utilization and development. These principles have been underlined in the Convention on Biological Diversity and the European efficiency resources towards 2050. Thus critical issues are now to understand the distribution and extent of genetic diversity available to breeders and stakeholders, the kind and range of characterization, how to face the problem of continuous expanding of germplasm to be conserved. Focusing on the case study of hazelnut which is a crop of great importance for European countries, the paper describes a resourceful strategy for re-organizing and sharing hazelnut genetic resources through an upgrading of knowledge on their value and uses. The paper summarizes the progresses so far and provides a 'launching pad' for future researches. The brief review discusses also the recent progresses in recovery, characterization conservation and uses of European hazelnut germplasm achieved by 068 AGRI GEN RES SAFENUT which was one of the 17 Action financed by the European Commission-Directorate General for Agriculture and Rural Development. The current status on the morphological and molecular characterization of the in situ and ex situ of the most important European collections, the rescue and preservation of new accessions recovered on farm were discussed underling critical aspects. A better understanding of hazelnut genetic diversity and its distribution is essential for its conservation and use as well as the harmonization of the morphological and biochemical descriptors. The importance of traditional knowledge is also considered as integrated part of the multidisciplinary approach useful to rationalize genetic resources maintained in the collections. Thus improving the characterization on cultivated and wild forms through the development of a core collection, is the further step to achieve a more effective management and use of European nuts germplasm.

The hazelnut (Corylus avellana) is one of the most important crops in the Mediterranean basin. The availability of efficient and reliable in vitro propagation could valorize the local genetic resources. Different studies have been carried out for the definition of an efficient hazelnut micropropagation protocol. These have usually been performed on the most important cultivars, but the application of the micropropagation protocol to the minor ones has produced contradictory results and the technique sometimes had less success than the traditional one. The aim of this work was to gather knowledge and additional information on the in vitro performance of some minor cultivars in comparison with the most used for micropropagation. A revised procedure for the specific medium formulation is suggested. The sterilization and culture establishment phases are discussed in detail. The role of zeatin and 6-benzylamminopurine (BA) in shoot proliferation in the Italian traditional cultivars is compared to improve this phase. The rooting stage proves to be one of the most crucial steps in achieving a large-scale commercial application of hazelnut micropropagation.

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Hazelnut (Corylus avellana L.) is one of the most important tree nut crops in Europe. Germplasm accessions are conserved in ex situ repositories, located in countries where hazelnut production occurs. In this work, we used ten simple sequence repeat (SSR) markers as the basis to establish a core collection representative of the hazelnut genetic diversity conserved in different European collections. A total of 480 accessions were used: 430 from ex situ collections and 50 landraces maintained on-farm. SSR analysis identified 181 genotypes, that represented our whole hazelnut germplasm collection (WHGC). Four approaches (utilizing MSTRAT, Power Core, and Core Hunter's single-and multi-strategy) based on the maximization (M) strategy were used to determine the best sampling method. Core Hunter's multi-strategy, optimizing both allele coverage (Cv) and Cavalli-Sforza and Edwards (Dce) distance with equal weight, outperformed the others and was selected as the best approach. The final core collection (Cv-Dce30) comprised 30 entries (16.6% of genotypes). It recovered all SSR alleles and preserved parameter variations when compared to WHGC. Entries represented all six gene pools obtained from the population structure analysis of WHGC, further confirming the representativeness of Cv-Dce30. Our findings contribute towards improving the conservation and management of European hazelnut genetic resources and could be used to optimize future research by identifying a minimum number of accessions on which to focus.

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