Genetic diversity of Cytospora schulzeri isolates using RAPD-PCR and MP-PCR markers on Apples of Semirom Region of Iran

Genetic diversity relationships of ۵۰ isolates of Cytospora schulzeri on apple from different parts of the Semirom region were analyzed using ۱۵ polymerase chain reaction (PCR) based markers, ۷ random amplified polymorphic DNAs (RAPDs) and ۸ Microsatellite primed polymerase chain reaction (MP-PCR). Using ۷ selected RAPD primers ۱۱۳ bands were generated, of which ۸۱ bands were polymorphic (۷۱.۷%), with an average of ۱۱.۵۷ polymorphic fragments per primer, and with ۸ selected MP-PCR primers ۱۰۷ amplified bands were observed with ۷۸ polymorphic bands (۷۲.۳%), with an average of ۹.۷۵ polymorphic fragments per primer. In RAPD marker, number of polymorphic bands varied from ۸ (۲۴۱) to ۱۵ (۲۳۰, ۲۳۸, OPA۱۳) with an average of ۱۱.۵۷ per primer and which varied in size from ۲۰۰ to ۳۷۵۰ bp. Percentage of polymorphism ranged from ۶۴% (۲۰۳ and ۲۳۲) to a maximum of ۸۳% (۲۳۸). In MP-PCR marker, number of polymorphic bands varied from ۶ (CAG) to ۱۲ (GTG and ATG) with an average of ۹.۷۵ per primer and which varied in size from ۲۰۰ to ۳۵۰۰ bp. Percentage of polymorphism ranged from ۵۴% (CAG) to a maximum of ۸۱% (ACTG). By combining markers, a total of ۲۲۰ bands were detected, of which ۱۵۹ bands (۷۲%) were polymorphic and produced on an average ۱۰.۶ 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 ۰.۵۴ to ۰.۸۹ in RAPD, ۰.۶۲ to ۰.۸۹ in MP-PCR and ۰.۶۲ to ۰.۸۷ with combined markers based similarities. High cophenetic correlation between the similarity matrix and corresponding dendrogram was obtained by RAPD + MP-PCR marker (r = ۰.۸۱). 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.

Keywords:

Apple , cytospora , genetic diversity , MP-PCR , RAPD