C. arabica accessions conserved in the CATIE genebank were classified in three groups on the basis of their genetic origins: coffee trees from the centre of origin of the species ; Typica- and Bourbon-derived varieties and mutants ; and introgressed lines selected within interspecific hybrid progeny (C. arabica x Coffea spp.). The results of the assessment and characterization of these resources highlighted features specific to each of these groups with respect to their innate genetic diversity and extent of polymorphism. The genetic resource assessment data discussed in this chapter could now be used to build core collections for long-term germplasm conservation, evaluation and exchange purposes