Genetic diversity of Valsa malicola isolates assessed by microsatellite-primed PCR (MP-PCR)

Genetic diversity of 40 isolates of Valsa malicola in Iran was investigated by MP-PCR. Isolates were obtained from different host plants in diverse regions during 2004–2010. Of the six microsatellite primers tested, only four primers; (ACTG)₄, (GACA)₄, (AC)₈ and (CGA)_5, were able to amplify DNA fragments. With these four primers, 120 loci were identified; of which eight were monomorphic (6.7%) and 112 were polymorphic (93.3%). Approximate size of amplified DNA fragments ranged from 0.2 to 3?kb. Observed high genetic diversity in isolates of V. malicola indicates the eligibility of the marker to investigate ranks below the species level. The results of cluster analysis indicated that isolates are related to each other with 45.63% similarity and four groups (1, 2, 3 and 4) were identified in the dendrogram. Group 3 included 37 isolates that were obtained from different hosts and geographical regions and each of groups 1, 2 and 4 only had one isolate. Some correlations between identified groups and host origins or geographic distributions of the isolates were found.