Genetic variation in wild and cultivated artichoke revealed by RAPD markers

Determination of intraspecific genetic diversity is an important first step for the utilization of genetic resources and can provide useful information on crop evolution. A living collection of Italian and foreign artichoke varieties and ecotypes is maintained at the Germplasm Institute, Bari, Italy. A total of 32 accessions of cultivated (Cynara cardunculus L. var. scolymus (L.) Fiori), three of wild (Cynara cardunculus var. cardunculus L.) artichoke and two of cultivated cardoon (Cynara cardunculus var. altilis L.) were analysed in order to study genetic variation and relationships within the species, using RAPD markers. Cultivated accessions were selected according to morphological variation and geographical distribution available in the collection. Fifty arbitrary decamer primers were initially tested, 18 of which showed from 3 to 10 unambiguously interpretable fragments. An intra-accession analysis using 4 varieties and 8 polymorphic primers revealed that no RAPD variation was detected among individuals. Jaccard's similarity index (JSI) was comprised among 1 and 0.693 when all accessions were considered, on the other hand, within the cultivated artichoke, JSI ranged between 1 and 0.817. A UPGMA dendrogram based on the similarity matrix showed that wild artichokes were clearly separated from cultivated accessions. Moreover, within cultivated artichokes, several groups could be distinguished.