Assessing genetic diversity and population structure of Iranian melons () collection using primer pair markers in association with resistance to Fusarium wilt.

We evaluated genetic diversity and population structure of Iranian melons (Cucumis melo L.) using combinations of 35 primer pairs: 15 Simple-Sequence-Repeats (SSR); 10 Inter-Simple-Sequence-Repeats (ISSR); and 10 Sequence-related amplified polymorphism (SRAP) markers in association with resistance to melon Fusarium wilt, caused by Fusarium oxysporum f. sp. melonis (FOM ). Genetic similarity was determined by simple matching coefficient (SSM) and dendrogram by clustering-analysis with unweighted pair groups using arithmetic averages (UPGMA). By combining ISSR-SSR-SRAP markers, a high degree of variation among the melons was detected. The mean polymorphism information content (PIC), marker index (MI), effective-number of alleles (I), expected heterozygosity (H), and Nei's gene diversity parameters were 0.392, 0.979, 1.350, 0.551 and 0.225, respectively. According to MI, PIC, I, H, and Nei indices evaluation, ISSR6, ISSR9, SRAP3, SRAP5, SSR3 and SSR6 had the best performance in genetic diversity of the related melons population. The 35 primers yielded a total of 264 bands, of which 142 showed polymorphism. Clustering of genotypes based on resistance to Fusarium wilt, and comparison with grouping on SSR, SRAP and ISSR marker revealed a significant compliance between disease severity and molecular marker dendrograms. Thus, increasing the number of molecular markers for genetic diversity provides a powerful tool for future agricultural and conservation tasks.