Mitochondrial variability was investigated in natural populations of wild carrot (Daucus carota ssp carota) in different regions: South of France, Greece, and various sites in the Mediterranean Basin and Asia. Total DNA was digested with two restriction endonucleases (EcoRV and HindIII) and probed with three mitochon-drial DNA-specific genes (coxI, atp6, and coxlI). Twenty-five different mitochondrial types were found in 80 analyzed individuals. Thirteen mitotypes were found among the 7 French populations studied. On average, 4.4 different mitotypes were observed per population, and these mitotypes were well-distributed among the populations. All of the mitochondrial types were specific to a single region. However, the proportion of shared restriction fragments between 2 mitotypes from different regions was not particularly lower than that which occurred among mitotypes from a single region. On the basis of the sexual phenotype [male-sterile (MS) or hermaphrodite] of the plants studied in situ and that of their progeny, 2 mitotypes were found to be highly associated with male sterility. Eighty percent of the plants bearing these mitotypes were MS in situ, and all of these plants produced more than 30% MS plants in Communicated by R. Hagemann J. Ronfort ([]) D6partement de biologie des populations, Centre d'Ecologie Fon-ctionnelle et Evolutive (CEFE), CNRS, 1919, Route de Mende, B.P. 5051-34033 Montpellier Cedex France P. Saumitou-Laprade Laboratoire de G6netique et Evolution des populations v6g6tales, 237, Universitb Paris vi, 75252 Paris Cedex France their progeny. This association with male sterility was consistent in several populations, suggesting an association with a cytoplasmic male-sterility system. Moreover , these two mitotypes had very similar mitochon-drial DNA restriction patterns and were well-differentiated from the other mitotypes observed in wild plants and also from those observed in the two CMS types already known in the cultivated carrot. This suggests that they correspond to a third cytoplasmic sterility. Key words RFLP 9 Mitochondrial DNA diversity 9 Natural populations 9 Cytoplasmic male sterility 9 Daucus carota L.