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...