In order to identify possible mislabeling of the apple accession maintained ex situ in Srebrenik and to gain insight into the genetic structure of the conserved germplasm, 14 accessions from the collection were genotyped using 10 SSR (Simple Sequence Repeats) markers. Obtained SSR profiles were then added to an existing database constructed for previously characterized 24 traditional and 13 international, reference apple cultivars maintained at the same collection. Bayesian analysis implemented in the STRUCTURE program grouped 42 out of 51 analyzed apple accessions (38 traditional and 13 international) into three RPPs (reconstructed panmictic populations) with probability of membership qI higher than 75%. Almost all international, reference cultivars grouped in RPP3, whereas traditional B&H cultivars from the Srebrenik collection grouped in all three RPPs. Large and significant differentiations between all three individual RPPs were detected through the analyses of molecular variance and confirmed with FCA (factorial correspondence analyses). NJ cluster analysis, based on the Bruvo genetic distance, revealed that out of 38 traditional B&H apple cultivars, analyzed in the study, ‘Ljepocvjetka’, ‘Bobovec’ and ‘Bobovec J’ grouped closest to the international reference cultivars. Available date indicates that unlike a large number of B&H apple cultivars which were introduced during the reign of the Ottoman Empire, ‘Ljepocvjetka’ and ‘Bobovec’ were probably introduced at a later date. Cluster analyses also enabled the detection of one synonym and three homonyms within the collection. In four cases, previously conducted identification based on phenotypic analyses was confirmed by genetic analyses. Results of the structure analyses indicate a heterogeneous genetic structure of the analyzed accessions. This characteristic of the B&H apple germplasm could be useful for future breeding programs.

There is a need for classifying and conserving local apple cultivars from two main regions in Bosnia and Herzegovina (BH P < 0.001). Analysis of the genetic structure indicates that overall, approximately half of the local apple cultivars from Sarajevo and eastern Bosnia (52% and 45%, respectively) grouped in the RPP1 consisting mainly out of international reference cultivars, whereas the other half grouped in the RPP2 with traditional B&H reference cultivars. Both neighbor joining (NJ) cluster analysis based on Bruvo genetic distance and factorial correspondence analysis (FCA) confirmed the results of the genetic structure analysis. The molecular data show that both apple accessions from Sarajevo and from eastern Bosnia represent an interesting source of diversity, which needs to be conserved.

Summary The aim of this work was to investigate the influence of cultivar and storage time on the total phenol content (TPC) of three actual apple cultivars (Topaz, Pinova, Pink Lady) and three autochthonous apple cultivars (Ruzmarinka, Ljepocvjetka, Paradija) as well to determine their physical and chemical characteristics. Total phenol content has been determined by Folin- Ciocalteu reagent during cold storage at 1 °C, for 60 days. Changes of apple juice samples phenolics in relation to oxidation time after pressing (0 hours, 2 h and 4 h) were examined. A significant variation in content of phenols in apple cultivars under investigation was noted. Paradija, autochthonous apple contained the highest content of phenols (1.003 g GAE/L), while Topaz, actual apple cultivar had the lowest content (0.596 g GAE/L), during the storage time. TPC of apple cultivars stayed at a relatively constant level during the storage, with the exception of Pink Lady and Paradija apples, where TPC changed significantly during cold storage. The level of TPC in cloudy apple juice samples of all apple cultivars decreased during the oxidation time after pressing.