Investigate the Genetic Relationships and Morphological Diversity of Some Afghan and Iranian Melon Cultivars for Breeding Purposes

To investigate the genetic diversity of 40 melon and cantaloupe cultivars, which were collected from the central regions of Iran and southwestern Afghanistan, inter-simple sequence repeat (ISSR) primers and several morphological traits were used. The results demonstrate that 12 selected ISSR markers generated polymorphic bands with a distinct band pattern. There were a total of 150 bands created, with 95 bands exhibiting polymorphism (62.44% diversity). Based on shape and characteristics, cluster analysis and principal coordinate analysis (PCoA) classified the cultivars into five groups: winter and late ripening, medium ripening, sweet, and early melons, including cantaloupe and melon. In the majority of instances, PCoA was consistent with cluster analysis, whereas the molecular data did not perfectly match the morphological results. The results of the analysis classified the morphological characteristics of individuals into five groups: the first group comprised nine Iranian and Afghan melon genotypes with long, thin-skinned forms and intermediate medium ripening, and the second group comprised five Afghan melon genotypes with late ripening, winter ripe, and thick skin and flesh. The third group of 11 Iranian and Afghan melon cultivars was typically medium-sized, elliptical-shaped melons with thin skin. The fourth group consists of two Iranian melons with small seeds, small fruit, rapid maturation, and no flavor. The final group possessed dense and tender flesh, a spherical shape, and large seeds. In conclusion, morphological traits and ISSR analysis could be useful tools for classifying melon germplasm for future breeding applications. The morphological and molecular similarities between Afghan and Iranian cultivars suggest their origin.