INRA, Unite de Genetique et Amelioration des Fruits et Legumes Centre de Recherches d’Avignon Domaine Saint Maurice 84143 Montfavet cedex France Keywords : Prunus armeniaca , genetic resources, characterization, diversity, genetic erosion Abstract Apricot is widely cultivated in Tunisia showing a large variability among apricot landraces. Recent surveys performed in the main areas, lead to the identification of 112 accessions, 76 grafted ones issued from the northern, central, and south-eastern areas, and 36 seed-propagated ones, called ‘Bargougs’, encountered in the oasian areas. Their characterization has been assessed with morphological characters by using a subset of the UPOV descriptor, based on fruit and leaves quantitative traits. The apricot landraces characterization allowed the identification of a large variability w,hich is structured in two main groups related to fruits characters and enabled the distinction between ‘Bargougs’ accessions and varieties. Within the variety group, homogenous sub -groups have been highlighted and defined as ‘population cultivar’. Some original and interesting characters have been identified related to fruit colour, fruit shape and aroma; they will be useful for future breeding programs. Tremendous genetic erosion has been shown in the Tunisian apricot landraces by comparison with previous studies. This has to be taken in consideration by the creation of an accurate genetic resource collection. INTRODUCTION Apricot is an important fruit tree species in Tunisia. It is cultivated in the north, centre, south, and in the oasian areas. However due to adaptation factors, a strong interaction exists between cultivars and areas of cultivation. Thus, many apricot landraces were limited to traditional orchard and some old plantations, and are unknown outside of their area of cultivation. Apricot material is mainly propagated by grafting in Tunisia except in the oasian areas where material called ‘Bargougs’ is propagated by seeds. The present work, based on a new survey of the Tunisian apricot areas, aims to illustrate the actual apricot variability in Tunisia, to characterize the Tunisian apricot germplasm and to evaluate the impact of genetic erosion among traditional varieties by comparison with previous works. MATERIAL AND METHODS Plant Material Surveys of Tunisian apricot landraces from northern (Testour, Ras Jbel), central (Kairouan, Sfax, Mahdia) and southern (Gabes, Jerba, Mareth) areas as well as from oasis areas (Midess, Tozeur, Nefta, Degache, Tameghza, Gafsa) have been assessed. One hundred and twelve accessions have been identified: 76 grafted cultivars and 36 seedling apricot trees named ‘Bargougs’ issued from the Western oases of Tunisia (Table 1). ________________________