1Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
2Department of Plant Protection, Faculty of Agricultural Science and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Genetic diversity relationships of 50 isolates of Cytospora schulzeri on apple from different parts of the Semirom region were analyzed using 15 polymerase chain reaction (PCR) based markers, 7 random amplified polymorphic DNAs (RAPDs) and 8 Microsatellite primed polymerase chain reaction (MP-PCR). Using 7 selected RAPD primers 113 bands were generated, of which 81 bands were polymorphic (71.7%), with an average of 11.57 polymorphic fragments per primer, and with 8 selected MP-PCR primers 107 amplified bands were observed with 78 polymorphic bands (72.3%), with an average of 9.75 polymorphic fragments per primer. In RAPD marker, number of polymorphic bands varied from 8 (241) to 15 (230, 238, OPA13) with an average of 11.57 per primer and which varied in size from 200 to 3750 bp. Percentage of polymorphism ranged from 64% (203 and 232) to a maximum of 83% (238). In MP-PCR marker, number of polymorphic bands varied from 6 (CAG) to 12 (GTG and ATG) with an average of 9.75 per primer and which varied in size from 200 to 3500 bp. Percentage of polymorphism ranged from 54% (CAG) to a maximum of 81% (ACTG). By combining markers, a total of 220 bands were detected, of which 159 bands (72%) were polymorphic and produced on an average 10.6 polymorphic bands per primer. The results showed that both markers were suitable for the detection of genetic polymorphism among apple C. schulzeri isolates. Estimated genetic relationship using similarity co-efficient (Jaccard’s) values between different pair of accessions varied from 0.54 to 0.89 in RAPD, 0.62 to 0.89 in MP-PCR and 0.62 to 0.87 with combined markers based similarities. High cophenetic correlation between the similarity matrix and corresponding dendrogram was obtained by RAPD + MP-PCR marker (r = 0.81). Cluster analysis of the data using UPGMA based on Jaccard´s similarity coefficient, divided the isolates into six groups, showing a high genetic diversity among populations of C. schulzeri.