Molecular characterization of tomato cultivars

Randomly amplified polymorphic DNA (RAPD) markers can be useful in variety identification or to analyse the relationships among genotypes. RAPD analyses were conducted on 67 modem and vintage cultivated tomato accessions and eight accessions of wild Lycopersicon species, using six selected primers. Considering all the accessions, 104 bands, 58 of which polymorphic, were scored. Within cultivated L. esculentum, 68 total and 22 polymorphic bands were detected. Duplicate amplifications of the same DNA samples showed a high reproducibility of the RAPD protocol. Differences in RAPD profiles between seed lots of the same accession were seldomly observed. Cluster analysis allowed us to distinguish clearly L. esculentum from the wild species. Within L. esculentum, two major groups were identified, the first included all the fresh market varieties and the vintage processing varieties, and the second included most of the modern processing varieties. In the latter group, the dendrogram showed subgroups including standard varieties and their derivatives obtained through backcross or pedigree selection. RAPD analysis did not distinguish cultivars indicated as synonyms or selected from the same standard variety; in only a few cases, types clearly different at the phenotypic level were not discriminated. The RAPD approach showed considerable potential for tomato variety identification and discrimination.