Genetic analysis of Turkish apple germplasm using peroxidase gene-based markers

Plant peroxidases belong to a multigene family and posses highly conserved domains allowing to design oligonucleotide primers to amplify DNA sequences coding for peroxidases from plants with unsequenced genomes. Peroxidase gene-based polymorphism among Malus species, and correlation between peroxidase markers were deduced in this study. Turkish apple germplasm was evaluated using 14 peroxidase specific primers. Targeted-PCR amplification of genomic DNA from 192 apple genotypes available in the Turkish genetic resources yielded polymorphisms giving a similarity range from 0.56 to 0.98 with a mean of 0.77. Based on the POGP gene polymorphism, two distinct clusters were detected among the apple accessions, suggesting different evolutionary pathway. Correlation estimates as an indication of linkage disequilibrium between POGP markers ranged from −0.22 to 0.90, suggesting that few POGP markers were clustered and the remaining POGP markers evenly distributed throughout the apple genome. These results demonstrate that primers targeting the peroxidase gene family can be used to study genotypic diversity and evolutionary relationships on an intra- and inter-specific basis.