Population genetic structure of Aphis spiraecola Patch (Hem.: Aphididae) on citrus trees in Northern Iran

The spirea aphid, Aphis spiraecola Patch (Hemiptera: Aphididae), is a serious pest of citrus in northern Iran. It causes direct damage by sap feeding and extracting honeydew and also indirect damage by transmission of several virus diseases. The aim of this study was determining the relationship between genetic structure of different populations of A.spiraecola with its geographical distribution on citrus trees in northern Iran. The genetic structure of A. spiraecola collected on citrus trees in eight localities, was described by seven polymorphic microsatellite loci. Among 271 individuals, 195 multilocus genotypes were identified and the clonal diversity in populations were 0.5 to 0.93. They confirmed that A. spiraecola reproduces by cyclical parthenogenesis on citrus trees in North of Iran. The mean of Polymorphic Information Content was (PIC =0.62). There were significant deviations from Hardy-Weinberg equilibrium in all populations. The analysis of molecular variance revealed high intrapopulation and weak interpopulation genetic differentiation among geographic populations. Also, the UPGMA dendrogram of 8 populations based on Nei's genetic distance indicated no considerable genetic differentiation among them, which is in accordance with structural analysis. The findings of this research provide useful information about the genotypic distribution of A. spiraecola in Northern Iran which can be integrated with life cycle information of the pest and used in pest management programs.