Development of New SSR Markers for High-Throughput Analyses of Peach-Potato Aphid (Myzus persicae Sulzer)

The complex life cycle, high reproductive potential and ability to quickly develop resistance to insecticides are key factors contributing to the destructiveness of the peach-potato aphid (Myzus persicae Sulzer) among pest species. Monitoring its population dynamics at a large scale allows us to better understand M. persicae biology and take relevant measures for pest management. For this purpose, reliable molecular tools are needed. Based on the analysis of 128,362 microsatellite loci, we developed four multiplex assays including 49 comprehensively characterised SSR markers. Internal validation confirmed the species specificity and low genotyping error (e_a = 0.8%, e_l = 0.99%, e_obs = 22.7%) of the assays. A total of 194 alleles were identified (mean = 4 alleles per locus, range = 2-8 alleles per locus) within a group of 365 aphid accessions collected in the Vysočina region (Czechia). The studied aphid population showed the typical characteristics expected of the species with clonal or partially clonal reproduction (heterozygote excess, negative F_IS, moderate-to-high linkage disequilibrium (LD), and distortion of the H-W equilibrium for most of the loci), and did not exhibit any stratification on a spatiotemporal level. Owing to the high discriminatory power of the markers, we discovered that the population sample was founded upon a small number of fundatrices, as only five dominating lineages comprising over 70% of all accessions were identified. In conclusion, this study identified a significant number of new high-quality markers with the high discriminatory power necessary for revealing the population structure and dynamics of M. persicae, which holds considerable potential in both general biological and agricultural research.