Genetic diversity of local cultivars of melon (Cucumis melo L.) collected in Southern Tunisia: Valorization for a selection and genetic conservation program

This work has the objective to study the genetic diversity and to evaluate the agronomic potential of local melon cultivars. The morphological characterization of 22 local cultivars of melon based on 32 traits showed that they differ from the commercial variety Ananas. Indeed, the local cultivars are characterized by an early production, larger size and low sugar content of fruit. The genetic diversity of the melon cultivars, assessed using four RAPD markers, showed a polymorphism rate of 95 %. The PCA analysis according to the first three axes which explain 54.7% of total variability indicates a clear distinction between the Ananas variety and the local cultivars. The correlations between distance matrices of the morphological and the molecular data showed that the fruit length, fruit diameter, size of pistil scar and maximum thickness of flesh are significantly correlated with some RAPD markers. This study showed the clear distinction of the local melon cultivars in comparison to the commercial one, which has practical impact by the use of local genotypes to improve some traits in the commercial melon cultivars.