Chromosome-Level Assemblies of Three Candidatus Liberibacter solanacearum Vectors: Dyspersa apicalis (Förster, 1848), Dyspersa pallida (Burckhardt, 1986), and Trioza urticae (Linnaeus, 1758) (Hemiptera: Psylloidea)

Abstract

Psyllids are major vectors of plant diseases, including Candidatus Liberibacter solanacearum (CLso), the bacterial agent associated with “zebra chip” disease in potatoes and “carrot yellows” disease in carrot. Despite their agricultural significance, there is limited knowledge on the genome structure and genetic diversity of psyllids. In this study, we provide chromosome-level genome assemblies for three psyllid species known to transmit CLso: Dyspersa apicalis (carrot psyllid), Dyspersa pallida, and Trioza urticae (nettle psyllid). As D. apicalis is recognized as the primary vector of CLso by carrot growers in Northern Europe, we also resequenced populations of this species from Finland, Norway, and Austria. Genome assemblies were constructed using PacBio HiFi and Hi–C sequencing data, yielding genome sizes of 594.01 Mbp for D. apicalis; 587.80 Mbp for D. pallida; and 655.58 Mbp for T. urticae. Over 90% of sequences anchored into 13 pseudo-chromosomes per species. D. apicalis and D. pallida assemblies exhibited high completeness, capturing over 92% of conserved Hemiptera single-copy orthologs. Furthermore, we identified sequences of the primary psyllid symbiont, Candidatus Carsonella ruddii, in all three species. Gene annotations were produced for each assembly: 17,932 unique protein-coding genes were predicted for D. apicalis; 18,292 for D. pallida; and 16,007 for T. urticae. We observed significant expansions in gene families, particularly those linked to potential insecticide detoxification, within the Dyspersa lineage. Resequencing also revealed the existence of multiple subpopulations of D. apicalis across Europe. These high-quality genome resources will support future research on genome evolution, insect–plant–pest interactions, and disease management strategies.