Phoenix dactylifera L. is widely distributed and performs an important socioeconomic role in the south of Tunisia.The objective of this work was to evaluate different methods of estimating the diversity and genetic structure of Tunisiandate palm subpopulations. Nine morphological traits and five SSR loci were used to study morphological and genetic diversity. Correlations between phenotypic and genetic distances were assessed. Analyses of variance of the morphological data reveal significant differences among subpopulations for all traits measured. The Mantel test shows that morphological variation is correlated with fruit maturity period (r = 0.161; p = 0.020). Analysis of molecular variance reveals significant genetic variation among fruit-consistency subpopulations (p < 0.05) and the Mantel test emphasises a correlation between genetic distance and fruit consistency (r = 0.110; p = 0.029). This information will be useful for germplasm collection, for conservation and for various date palm culture programmes in the Tunisian continental oases.

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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.