In the present work, agro-morphological characteristics, essential oil composition and randomly amplified polymorphic DNA (RAPD) markers were studied to estimate the relationships among 12 basil (Ocimum basilicum L.) genotypes, belonging to nine known cultivars grown in Italy. The basil cultivars were distinguished on the basis of agro-morphological determinations and constituents of essential oil. Chemical compounds of essential oils were found variable in the various basil cultivars. As a consequence, the plants were classified into main phenotypes and chemotypes. RAPD markers were used in order to assess the genetic relatedness among the basil cultivars. On the basis of their genetic similarities, RAPD analysis allowed to group the samples into two main clusters. One of these included cultivars suitable for food industry, which were also correlated via agro-morphological features. However, the same cultivars produced distinct essential oil profiles, which did not match with results obtained by agronomic and genetic analysis. This fact, maybe, is due to a different genic expression of the key enzymes involved in biosynthetic pathways that produce chemical compounds.
