## 4 Discussion  
Germplasm genetic diversity is necessary to search for phenotypic and genetic resources and plays an important role in the sustainability and improvement of crop breeding [29]. The microsatellite markers used in this study to evaluate the genetic diversity of selected apricot cultivars from Slovak and Austrian gene banks and to create the SSR database were originally developed from the peach genome [10; 19; 20] and have been available for more than two decades. Since then, markers have been designed directly from the apricot genome [30; 31; 32; 33; 34], which have also been successfully used to detect their polymorphism [2; 16; 35]. However, microsatellite markers from the peach genome are still being used to detect polymorphism in apricot [2; 5; 17; 36; 37; 38] as well as cross-transferable polymorphism in the whole genus _Prunus_[6; 20; 39]. Even microsatellites with longer core repeats (3-nt or more), which have been successfully tested in apricot and are now preferred, have been isolated in peach [40]. In our study, the application of 11 selected highly polymorphic SSRs revealed a high degree of polymorphism in 53 apricot genotypes. This is evident from the expected heterozygosity (_He_) and polymorphic information content (_PIC_). Markers with an expected  
Figure 5: Plots expressing the agreement or the closest similarity of apricot samples collected from orchards in Slovakia and Austria with a declared cultivar name (**A**) and of apricot samples from the random collection and bought in a shop without a declared cultivar name (**B**). heterozygosity of 0.5 or less are not very useful for large-scale analysis, and _He_ was calculated using an unbiased formula from allele frequencies [41]. Similarly, the polymorphic information content was calculated from allele frequencies and represents the ability to detect genetic variation between individuals within a population. It is a measure of informativeness with respect to expected heterozygosity [42]. According to [PERSON] et al. [42], codominant markers with _PIC_ values above 0.5 are highly informative. In our case, the least informative locus was UDP96-019, whose values for _He_ and _PIC_ were 0.607 and 0.592, respectively. The mean _He_ calculated from the eleven markers used was 0.811. In our study, based on the Structure analysis and the dendrogram, the distribution of apricot cultivars into three clusters (green, red, and blue) largely reflects their country of origin and/or pedigree, as has been found previously by many authors [5; 12; 13]. The green cluster can be classified as \"Central European\" (Slovakia, Hungary, Czechia, and Austria), and the cultivars assigned there mainly originated from this region or have cultivars from this region in their pedigree. Their main link is the old Hungarian cultivar 'Hungarian Best' ('Madarska,' Ungarische Beste'). The local cultivars 'Sabinovska' and 'Rakovskeho' in Slovakia, 'Velkopavlovicka' in Czechia, and 'Klosterneuburger' in Austria are closely related to 'Hungarian Best', and all are in one subgroup of the green cluster. In contrast with the results of [PERSON] et al. [14], we found that 'Hungarian Best' and 'Klosterneuburger' are different cultivars, but closely related, similar to the results of [PERSON] et al. [15]. In contrast to the results of [PERSON] et al. [43], we were able to distinguish the cultivars 'Sabinovska', 'Velkopavlovicka', and 'Madarska'. The second subgroup of the green cluster contains the Hungarian cultivar Budapest and the Slovakian cultivars 'Velbora' and 'Veharda', all of which have 'Hungarian Best' or 'Madarska' in their pedigree. The third subgroup of the green cluster contains the French cultivars 'Angeat', 'Frisson', and 'Bergeron', possibly reflecting their common origin in Central Europe. The cultivar 'Bergeron' is often \"placed\" in the \"Hungarian Best\" group by many authors [2; 15; 44; 45; 46]. The cultivar 'Vinoslivyj' from the red group stands out among old Central European cultivars, as noted also by [PERSON] et al. [45].