In Romania, work on identification, conservation and evaluation of fruit genetic resources activities was initiated in 1970 in order to limit the loss of biodiversity. There are rich sources of germplasm located in two research centres: RIFG Pitesti with 642 accessions and UCv-SCDP Vâlcea with 361 accessions, representing wild species, local populations, named cultivars, breeder’s selections and rootstocks. Observations were made according to the IBPGR Prunus descriptors updated by the ECP/GR Prunus Working Group. The following genetic resources from the Piteşti and Vâlcea collections were used in a breeding programme in the development of several plum cultivars: ‘Grase de Becs’, ‘Carpatin’, ‘Ialomiža’, ‘Kirke’, ‘Wilhelmina Späth’ (for resistance / tolerance to Plum pox virus); ‘Vinete romāneşti’, ‘Tuleu timpuriu’, ‘Anna Späth’ (for late blooming), ‘Tuleu gras’, ‘Vâlcean’ (for fruit quality), ‘Stanley’, ‘Pescăruş’, ‘Centenar’ (for productivity), and ‘Diana’ (for self-fertility). The plum rootstock breeding programme used the following genotypes as sources of genes: ‘Rosior văratec’, ‘Brompton’, ‘Renclod Verde’, ‘Pixy’, ‘Saint Julien A’, ‘Albe mici’, ‘Scolduş’, ‘Porumbar’, etc. Breeding using the germplasm in these collections resulted in the release of 40 cultivars and 11 generative and vegetative rootstocks.