DNA barcode identification of lichen-forming fungal species in the Rhizoplaca melanophthalma species-complex (Lecanorales, Lecanoraceae), including?five?new species

摘要

Recent studies using sequence data from multiple loci and coalescent-based species delimitation have revealed several species-level lineages within the phenotypically circumscribed taxon Rhizoplaca melanophthalma sensu lato. Here, we formally describe five new species within this group, Rhizoplaca occulta, Rhizoplaca parilis, Rhizoplaca polymorpha, Rhizoplaca porterii, and Rhizoplaca shushanii, using support from the coalescent-based species delimitation method implemented in the program Bayesian Phylogenetics and Phylogeography (BPP) as the diagnostic feature distinguishing new species. We provide a reference DNA sequence database using the ITS marker as a DNA barcode for identifying species within this complex. We also assessed intraspecific genetic distances within the six Rhizoplaca melanophthalma sensu lato species. While intraspecific genetic distances within the five new species were less than or equal to the lowest interspecific pairwise comparison values, an overlap in genetic distances within the Rhizoplaca melanophthalma sensu stricto clade suggests the potential for additional phenotypically cryptic lineages within this broadly distributed lineage. Overall, our results demonstrate the potential for accurately identifying species within the Rhizoplaca melanophthalma group by using molecular-based identification methods.