The genusOlea: molecular approaches of its structure and relationships to other Oleaceae

Abstract
Ribosomal DNA RFLP and RAPD polymorphisms were examined in taxa belonging to Oleaceae genera. The objective of this study was to determine the taxonomic position of the genus Olea and of its components: subg. Olea section Olea, subg. Olea section Ligustroides, subg. Paniculatae and subg. Tetrapilus. Ribosomal DNA polymorphisms supported that O. subg. Tetrapilus was separated from other Olea species and appeared close to other Oleaceae genera as Nestegis, Chionanthus and Phillyrea. Moreover, RAPDs enabled us to distinguish the four groups of the genus Olea and O. subg. Tetrapilus was also closer to Nestegis and Chionanthus than to the other Olea species. Thus, Tetrapilus should be considered as a genus. Our results sustained the common origin of the sections Ligustroides and Olea.