Abstract The study of genetic diversity within the olive- tree (cultivated and wild forms) may be useful to reveal agronomic traits in the wild germplasm and to try to un- derstand the history of the olive-tree domestication. In this way, a study of nuclear and mitochondrial DNAs of cultivated and wild olives from two Corsican and Sardin- ian Mediterranean islands was performed using RAPD and RFLP markers. Our results show that most of the va- rieties and most of the oleasters were separated using the UPGMA dendrogram based on the Nei and Li similarity index. Most of oleasters carried either the MOM or MCK mitotype, characteristic of olives in the Western Mediter- ranean, whereas most of the varieties carried the ME1 mitotype, characteristic of olives in the East Mediterra- nean. The results indicate that the combination of mito- type and RAPD markers can be used as a powerful tool for differentiating two groups in the wild forms: the Western true oleasters and the feral forms. The true ol- easters are characterized by a Western mitotype and a Western RAPD pattern. Feral forms originate either from varieties or from hybridisation between a variety and an oleaster. Consequently, as expected, some of them aggre- gated with the varieties from which they were derived. The other feral forms are clustered with the oleasters and were detected only by their mitotype determination. This study has also permitted us to differentiate two popula- tions of cultivated olives in Corsica: one with close rela- tionships with Italian varieties (influenced by the East) and one selected from local oleasters probably due to a better local adaptation than foreign varieties. Keywords Olea europaea L. · mtDNA RFLP · RAPD · Mitotypes · Feral form · Wild olive populations Introduction The olive-tree (Olea europaea L.) is one of the most an- cient of cultivated trees. Two forms exist: the cultivated form (O. europaea subsp. europaea var. sativa) and the wild form (O. europaea subsp. europaea var. oleaster). In olive cultivation, the intensive modes of production favour the use of a few varieties with a stable and regular yield over a wide area associated with acceptable orga- noleptic characteristics. This selection leads to genetic erosion due to the abandonment of numerous locally adapted olive varieties. However, it is necessary to pre- serve the genetic diversity within the olive and the ole- aster in order to develop improvement programs and to determine the relations between the cultivated and wild forms, and in some cases also to reconstitute the olive history. Because of early olive cultivation, the cultivated forms, which have extended considerably over the natu- ral populations, have caused the regression of oleasters. Consequently, at the present time, oleasters are absent from many regions (Ouazzani et al. 1993), and are limit- ed to restricted areas along the shores of the Mediterra- nean (Zohary and Spiegel-Roy 1975). However, the study of oleasters appears of real interest since it might constitute a gene pool useful for olive improvement pro- grams, i.e. for disease and stress resistance. Cultivated and wild forms have the same chromosomes number (2 n = 46) (Green and Wickens 1989) and are fully inter-fertile. Cultivated olives are propagated vegetatively whereas wild olives only reproduce by sexual means. The cultivated forms have been selected from the wild local forms in several Eastern places (Zohary and Spiegel-Roy 1975). The domestication of the olive-tree started in the Near East about 6,500 years ago and has been disseminat- ed all around the Mediterranean basin (Zohary and Spiegel-Roy 1975; Loukas and Krimbas 1983). Recently, however, Besnard and Bervillé (2000) suggested other Communicated by H.F. Linskens V. Bronzini de Caraffa · J. Maury · C. Gambotti · J. Giannettini ( ✉ ) Centre de Recherche Biodiversité Insulaire Méditerranéenne, Laboratoire de Biochimie et de Biologie Moléculaire Végétales, Faculté des Sciences et Techniques, Université de Corse, BP 52, F20250 Corte, France e-mail: gianetti@univ-corse.fr Tel.: +33-4-95-45-01-80, Fax: +33-4-95-45-01-80 C. Breton · A. Bervillé INRA, UR-Génétique et Amélioration des plantes, Bat 33, 2 Place Viala, F 34060 Montpellier Cedex 1, France Theor Appl Genet (2002) 104:1209–1216 DOI 10.1007/s00122-002-0883-7 V. Bronzini de Caraffa · J. Maury · C. Gambotti C. Breton · A. Bervillé · J. Giannettini Mitochondrial DNA variation and RAPD mark oleasters, olive and feral olive from Western and Eastern Mediterranean Received: 5 June 2001 / Accepted: 7 August 2001 / Published online: 5 April 2002 © Springer-Verlag 2002