To respond to the needs of sustainable agriculture and forestry, it is necessary to preserve, among the plant species of the Atlantic Area, significant genetic diversity. The European Chestnut (Castanea sativa), the production of which makes possible the maintenance of agricultural and forestry activities in traditional rural areas, is an essential species, but one menaced by various diseases. The CASTANEA REG project proposes to study, in an organised manner, the genetic diversity of the Castanea sativa species in the three regions of the project, in order to create an Atlantic Network for the Study and Conservation of the Genetic Resources of the European Chestnut, which will help protect the chestnut, both at the level of the three countries involved, and at the European level. Achievements: ✔ Constitution of an initial cooperation network and trans-national and trans-regional coordination for management, characterisation, evaluation and preservation of the Genetic Resources and the biodiversity of the European chestnut tree, ✔ Standardisation of scientific methods and techniques, comparison of the plant life in the Atlantic Area regions using similar tools to avoid costly repetitions of manipulations in each country, ✔ Definition of a series of criteria and molecular markers necessary to describe the fruit tree varieties and the forest populations, ✔ Creation of a computer, or bio-computer, database, for molecular data. In the longer term it may be possible to feed this database with the DNA sequences of Castanea sativa, ✔ Automation (automatic sequencer) of the micro-satellite molecular markers (SSR), ✔ This project is an active approach to safeguard the Genetic Resources of the Atlantic Area. It gives preference to the use of the native species of chestnut in reforestation for example, rather than introducing varieties or genotypes that are foreign to Europe and considered as more efficient according to certain criteria. This approach is based on a desire for knowledge and exploitation of the genetic wealth of local varieties of chestnut, both cultivated and native populations, ✔ In total, 7 pilot meetings to monitor the work were organised during the project, ✔ In total, 8 publications in popular reviews (during the project the choice was to favour discussion meetings and vulgarisation), ✔ 3 publications in scientific journals, ✔ A website: http://cbi.labri.fr/outils/CastaneaREG/