Molecular characterization of some peach and nectarine hybrids by ISSR and SSR markers

The Prunus genus includes valuable fruit trees such as cherries, almonds, apricots, plums, peaches, and nectarines. Peaches and nectarines are among the most widely cultivated fruits globally and can adapt to temperate and subtropical climate conditions. In this study, 96 genotypes were analyzed using Simple Sequence Repeat (SSR) and Inter-Simple Sequence Repeat (ISSR) markers. These genotypes consist of hybrid VxÜ (VENÜS x ÜSTÜN) and hybrid RxÜ (STARK RED GOLD x ÜSTÜN) obtained through the hybridization of peach and nectarine varieties. For both VxÜ and RxÜ genotypes, 5 SSR and 14 ISSR primers were used. In the SSR marker analysis of hybrid VxÜ and RxÜ genotypes, 12 bands were obtained, all of which were found to be polymorphic, resulting in a polymorphism rate of 100%. The ISSR markers were also used for hybrid RxÜ and VxÜ genotypes, resulting in a total of 163 bands, of which 150 were polymorphic (yielding a 91% inter-genotypic polymorphism rate). Genetic similarity values among genotypes were calculated, and a UPGMA cluster analysis was performed to create a dendrogram. By analyzing the bands from all primer-variety combinations, a UPGMA dendrogram was generated to illustrate the similarity between the analyzed varieties and hybrid genotypes. The data and dendrograms obtained from genetic analysis were compared and discussed. Microsatellites and ISSR markers are recommended as robust and suitable molecular markers for peach and nectarine genetics and breeding.