Leaves of 22 accessions of olive (Olea europaea L.) from three named cultiv
ars (Manzanillo, Kalamata, and Verdale), and 17 accessions from cultivars w
ith names that are suspected to include synonyms (Corregiola, Corregiolo, F
rantoio, Frantoja, Frantojol, Nevadillo, Nevadillo Blanco, and Picual) were
obtained from Israel, Italy, the USA and Australia. Their genetic variabil
ity was investigated using random amplified polymorphic DNA (RAPD). Analysi
s of the PCR products was achieved by using the simple matching coefficient
and UPGMA clustering. 'Manzanillo' and 'Kalamata' showed a within-cultivar
genetic similarity of at least 98% irrespective of source. In contrast, 'V
erdale' showed a high genetic variability, with some accessions having less
than 80% similarity to others. 'Picual' and 'Nevadillo' (including 'Nevadi
llo Blanco'), which clustered at 69%, are possibly distinct cultivars. The
identity of 'Corregiola' and 'Frantoio' and their synonyms is uncertain. Co
nsidering the extent of the genetic distances involved between accessions w
ithin the 'Corregiola'/'Frantoio' group, and also within the 'Verdale' grou
p, it is likely that some of the within-group accessions are separate culti
vars.