## 4 Discussion
The red cluster can be categorized as \"cultivars with an Asian pedigree\", with samples from China and Central Asia clustered together similarly to the study by [PERSON] et al. [5]. Cultivars from Central Asia are in the first subgroup of the red cluster, together with the Slovakian cultivar 'Barbora', which is a combination of 'Madarska' and Central Asian cultivars. The second subgroup of the red cluster contains Chinese, Slovakia, and Czech cultivars which have the following in their pedigree: (i) the 'Madarska' cultivar crossed with the Central Asian cultivars; (ii) the 'Madarska' cultivar crossed with a mixture of pollen from Chinese cultivars; or (iii) a parent that comes from a cross of either (i) or (ii). It is interesting to note the position of the US cultivar 'Perfection' in the red cluster, which may reflect its Asian origin, as also found by [PERSON] et al. [35]. The blue cluster and its cultivars belong to the \"Western European and North American\" category, primarily consisting of French-bred and American cultivars. Unfortunately, the pedigree is known only for nine cultivars and is unknown for the others. Close relationships between Western European and North American cultivars have also been found by other authors and are consistent with their common origin from old European cultivars [2; 15; 35; 44]. The highest genetic distance resulting from the Structure analysis was found between the green (Central Europe) and blue (Western Europe and North America) clusters, lower between the green and the red (Central Asia and China), and lowest between the blue and the red clusters. In line with our results, also [PERSON] et al. [44] in their study placed the Hungarian cultivars (Central Europe) closer to the Central Asian group than to the other European cultivars. The Structure analysis of our data also showed that the average distances (expected heterozygosity) between individual cultivars in the same cluster were highest for the red (Central Asiaand China), lower for the blue (Western Europe and North America), and lowest for the green (Central Europe) cluster, similar to the results of [PERSON] et al. [35] and [PERSON] et al. [5]. We also found the highest \(He\) values in the China and Central Asia group when we divided the cultivars according to their geographical origin and we evaluated the allelic patterns across these geographical origin groups. The reason for the low diversity in the Central/Eastern Europe group is that apricots from this region are self-compatible, they are specifically adapted to winter frost (the northern limit of the apricot growing area), and most of them belong to a few prominent cultivar groups, or they have arisen from hybridization between them [35,44]. Another reason may be clonal production by grafting and vegetative propagation [45]. However, in our study, the Central European group of cultivars includes not only old local cultivars but also modern, mainly Slovak cultivars resulting from the hybridizations of old cultivars with cultivars from China and Central Asia, so the genetic diversity in this group (\(He\) 0.763) is not as low as was found in other studies (e.g., \(He\) 0.614 in [19] or \(He\) 0.441 in [16]). These results indicate that modern cultivars (hybrids) have increased the genetic diversity of the Central European group. The standard control database which we created with our SSR data was used to confirm the identity of the collected apricot cultivars with the declared cultivar names grown in commercial orchards in Slovakia and Austria. The identity of the apricot samples with their control counterpart was confirmed in 66% of cases, together with the closest similarity in 8% of cases, giving a total of 74%. This means that a total of 74% of the samples were identified with a high probability as the declared cultivars. The closest similarity with a control genotype other than the declared cultivar was in 21%, and the match with such a genotype was confirmed in 5% of cases.