Genetic Diversity in Iranian Melon Populations and Hybrids Assessed by IRAP and REMAP Markers

Retrotransposons (RTNs) constitute informative molecular markers for plant species because of their ability to integrate into a multitude of loci throughout the genome and thereby generate insertional polymorphisms between individuals. In the present study, RTN-based molecular markers, IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism), were applied to study RTN integration events and genetic diversity in ۱۰۰ melon genotypes (۸۸ genotypes from ۱۱ populations, three inbred lines, and ۹ hybrids). A total of ۹۴ and ۲۶۲ loci were amplified using ۵ IRAP and ۱۵ REMAP primers, respectively. The percentage of polymorphic loci (PPL) in populations ranged from ۳۹% (Zivari Shahrood) to ۴۸% (Shadegani E). The Mantel test between IRAP and REMAP cophenetic matrices evidenced no significant correlation (r= ۰.۲۹). IRAP+REMAP-based cluster analysis using UPGMA algorithm and Dice similarity coefficient depicted ۶ groups among ۱۰۰ melon genotypes. AMOVA revealed the higher level of genetic variation within populations (۶۷%) compared to among populations (۳۳%). The mean Fst values of all groups, except for group VI, were more than ۰.۲۰, demonstrating differentiation among the populations and genetic structure of the studied melon collection.

Keywords:

Cucumis melo , Genetic variability , Reme۱ , Retrotransposon