Characterization of microsatellite markers in the cosmopolitan lichen-forming fungus Rhizoplaca melanophthalma (Lecanoraceae)

Rhizoplaca melanophthalma s.l. is a group of morphologically distinct and chemically diverse species that commonly occur in desert, steppe and montane habitats worldwide. In this study, we developed microsatellite markers to facilitate studies of genetic diversity, population structure, and gene flow in the nominal taxon of this group, Rhizoplaca melanophthalma. We characterized 10 microsatellite markers using a draft genome of R. melanophthalma s. str. assembled from Illumina reads. These loci were tested for 21 R. melanophthalma s. str. specimens and also with a subset of 18 specimens representing six additional species in the R. melanophthalma complex. The number of alleles per locus in R. melanophthalma s. str. ranged from 3 to 11 with an average of 6.7. Nei's unbiased gene diversity ranged from 0.35 to 0.91. Amplifications of the microsatellite loci were largely successful in the other six species, although only three markers were found to be polymorphic. The new markers will provide an additional resource for studying genetic, population-and landscape-level processes in the cosmopolitan taxon Rhizoplaca melanophthalma s. str.