Geography has a greater effect thanWolbachiainfection on population genetic structure in the spider mite,Tetranychus pueraricola

Abstract

AbstractWolbachiais an intracellular symbiotic bacterium that infects various spider mite species and is associated with alterations in host reproduction, which indicates the potential role in mite evolution. However, studies ofWolbachiainfections in the spider miteTetranychus pueraricola, a major agricultural pest, are limited. Here, we used multilocus sequence typing to determineWolbachiainfection status and examined the relationship betweenWolbachiainfection status and mitochondrial diversity inT. pueraricolafrom 12 populations in China. The prevalence ofWolbachiaranged from 2.8 to 50%, and three strains (wTpue1,wTpue2, andwTpue3) were identified. We also found double infections (wTpue1 +wTpue3) within the same individuals. Furthermore, thewTpue1 strain caused weak cytoplasmic incompatibility (CI) (egg hatchability ~55%), whereas another widespread strain,wTpue3, did not induce CI. There was no reduction in mitochondrial DNA (mtDNA) or nuclear DNA diversity among infected individuals, and mtDNA haplotypes did not correspond to specificWolbachiastrains. Phylogenetic analysis and analysis of molecular variance revealed that the distribution of mtDNA and nuclear DNA haplotypes were significantly associated with geography. These findings indicate thatWolbachiainfection inT. pueraricolais complex, butT. pueraricolagenetic differentiation likely resulted from substantial geographic isolation.