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

Abstract

Retrotransposons (RTNs) constitute informative mole cular markers for plant species because of their ability to integrate into a multit ude of loci throughout the genome and thereby generate insertional polymorphisms between individuals. In the present study, RTN-based molecular markers, IRAP (inter-retrotrans poson amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism), were applied to study RTN integration events and genetic diversity in 100 melon genotypes (88 genotypes from 11 populations, three inbred lines, and 9 hybr ids). A total of 94 and 262 loci were amplified using 5 IRAP and 15 REMAP primers, respec tively. The percentage of polymorphic loci (PPL) in populations ranged from 3 9% (Zivari Shahrood) to 48% (Shadegani E). The Mantel test between IRAP and REM AP cophenetic matrices evidenced no significant correlation (r= 0.29). IRA P+REMAP-based cluster analysis using UPGMA algorithm and Dice similarity coefficient dep icted 6 groups among 100 melon genotypes. AMOVA revealed the higher level of genet ic variation within populations (67% ) compared to among populations (33% ). The mean Fst values of all groups, except for group VI, were more than 0.20, demonstrating di fferentiation among the populations and genetic structure of the studied melon collecti on. Keywords: Cucumis melo , Genetic variability, Reme1 , Retrotransposon.