Genetic diversity among Italian melon inodorus (Cucumis melo L.) germplasm revealed by ISSR analysis and agronomic traits

The genetic relationships among 13 melon inodorus populations that were collected in southern Italy were assessed using 100 inter-simple-sequence repeat (ISSR) primers and 15 morphological traits. The dihaploid line Nad-1 and the cultivar Charentais-T, both of which belong to the botanical variety cantalupensis, were used as reference accessions in the molecular analysis. A total of 358 polymorphic bands were obtained from 39 of the 100 ISSR primers used, and 15 phenotypic traits were scored and used for genetic-similarity calculations and cluster analysis. The resulting dendrograms based on the ISSR and phenotypic data allowed almost all of the melon genotypes to be distinguished on the basis of the skin colour of the fruits. Mantel's test revealed a good correlation between the morphological and molecular data in their ability to detect genetic relationships among melon ecotypes (r = 0.50, P = 0.99). The data obtained confirm the effectiveness of this approach, and open new perspectives to reveal possible molecular associations with the phenotypic traits analysed.