Evaluation of genetic variability in choosen apple (Malus x domestica Borkh.) cultivars by ISSR-PCR analysis.

The aim of the study was to determine the genetic variability in eight apple cultivars: Delikates, Cortland, James Grieve, Lired, Jonathan, Golden Delicious, Jonagold and Idared from the collection of Fruit Growing Research Station in Rajkowo of the West Pomeranian University of Technology, Szczecin. The cultivar Delikates was obtained from the crossing of two cultivars: Cortland and James Grieve, whereas cultivar Lired is a James Grieve's sport. The second one cultivar--Jonagold was obtained from the crossing of Jonathan and Golden Delicious. The cultivar Idared is a hybrid obtained from the crossing of Jonathan and Wagener. Out of 40 primers, 17 were chosen for the final study. Those amplified a total of 183 loci (872 amplicons) out of which 34 (18.5%) were monomorphic, 128 (69.5%) were polymorphic and 22 (12%) cultivar-specific. Specific ISSR products were detected for each apple cultivar. A dendrogram was constructed using the UPGMA method which revealed two distinct clusters: I--Delikates, Cortland, James Grieve and Lired, II--Jonathan, Golden Delicious, Jonagold and Idared. Genetic similarity between Delikates, Cortland and James Grieve was 68.6, 70.8%, respectively and between cultivar Jonagold, Jonathan and Golden Delicous was 79.8, 85.2%, respectively.