Genetic diversity of Paecilomyces variotii isolates by SSR marker in Kerman province, Iran

Die-back disease caused by Paecilomyces variotti is one of the most destructive diseases of pistachio in Iran. In this study, genetic diversity of Paecilomyces variotti isolates was investigated with SSR marker, using six primers pairs. Sampling was done from pistachio gardens in different geographical zones of Kerman province during summer 2013. Various fungal isolates were isolated from infected twigs on PDA. Based on the morphological criteria, seventy isolates were identified as P. variotii. These identifications were confirmed by sequencing data analysis. Twenty isolates were selected for the genetic diversity assay. A total of 22 alleles was identified with an average of two alleles per each primer pair. The mean of Nei's coefficient among isolates was 1.53. The average of Polymorphic Information Contents (PIC) for the SSR markers in P. variotti was 0.68. UPGMA Clustering grouped all the tested isolates into eight groups with a high genetic diversity. Based on these results, we can conclude that SSR markers are suitable for illustrating levels of genetic diversity within the isolates, but it is not adequate for demonstrating the relationship between a selected set of isolates and their related geographical regions.