Data from: Population structure of a vector-borne plant parasite

Parasites are among the most diverse groups of life on Earth, yet complex natural histories often preclude studies of their speciation processes. The biology of parasitic plants facilitates in situ collection of data on both genetic structure and the mechanisms responsible for that structure. Here, we studied the role of mating, dispersal and establishment in host race formation of a parasitic plant. We investigated the population genetics of a vector-borne desert mistletoe (Phoradendron californicum) across two legume host tree species (Senegalia greggii and Prosopis velutina) in the Sonoran desert using microsatellites. Consistent with host race formation, we found strong host-associated genetic structure in sympatry, little genetic variation due to geographic site and weak isolation by distance. We hypothesize that genetic differentiation results from differences in the timing of mistletoe flowering by host species, as we found initial flowering date of individual mistletoes correlated with genetic ancestry. Hybrids with intermediate ancestry were detected genetically. Individuals likely resulting from recent, successful establishment events following dispersal between the host species were detected at frequencies similar to hybrids between host races. Therefore, barriers to gene flow between the host races may have been stronger at mating than at dispersal. We also found higher inbreeding and within-host individual relatedness values for mistletoes on the more rare and isolated host species (S. greggii). Our study spanned spatial scales to address how interactions with both vectors and hosts influence parasitic plant structure with implications for parasite virulence evolution and speciation.Phoradendron californicum microsatellite dataMicrosatellite genotypes for Phoradendron californicum individuals collected from the field in Southern Arizona. Each row represents a unique P. californicum individual. Each individual has a site (location from which the mistletoe was collected), Host.Spp (full species name of the host on which it was collected), Latitude, Longitude, and peak calls of allele sizes for each of ten diploid loci. SRER= Santa Rita Experimental Range, CRP= Catalina Regional Park, TH=Tumamoc HillDryad.Microsatellite.Pcalifornicum.xlsxPcalifornicum Structure Input fileInput file for analysis of microsatellites in Structure. ReadMe file provides Structure parameters used in the analysis.project_dataFlowering phenology associated with Structure ancestryStructure ancestry results and day of first flowering. Each row represents a unique P. californicum individual. Each individual has a "MesAnc" (proportion of ancestry estimated to be from mesquite-associated cluster), "Host" (whether sampled from Acacia or Mesquite), and "DayofYear" (day of the year of first recorded flowering).PhenStruc.cs