Plant material of peach, situation in Spain The peach species is the most important stone fruit grown in Spain. The acreage devoted to this crop has increased lightly in the last 15 years, however the production has been doubled in this period as a consequence of the use of drip irrigation and introduction of new varieties and more efficient rootstocks. The range of varieties in Spain is very dinamic, there is a substantial increase of nectarines and platicarpa types, a light increase of melting peaches and a decrease of non-melting varieties. The main problems of this crop are the bad adaptability of many varieties from foreign countries to the Spanish environment, the dependency from varieties bred in other countries, the lack of internal quality of the fruits in many commercial cultivars, the incidence of pests, diseases and abiotic stresses and the high cost of the crop management. These problems might be overcame by means of breeding programs based on specific crosses. Currently, there are 14 active peach breeding programs in Spain. In terms of accomplishing the objectives of these programs new sources of variability carrying the desired traits are needed. The search and use of new sources of variation implies a high investment in research and characterization of the new plant material along with inheritance studies of those traits of interest.