Resolving the phylogenetic relationship betweenParmotrema crinitumandParmotrema perlatumpopulations

Abstract

AbstractThe widespread speciesParmotrema crinitum(Ach.) M. Choisy andParmotrema perlatum(Huds.) M. Choisy are mainly distinguished by their reproductive strategies. WhileP. crinitumpropagates by isidia,P. perlatumproduces soredia. In this study, we aim to evaluate the phylogenetic relationship between both species and to critically examine their species boundaries. To this purpose, 46 samples belonging toP. crinitumandP. perlatumwere used in our analysis, including 22 for which we studied the morphology and chemistry, before extracting their DNA. We used 35 sequences of the internal transcribed spacer region of nuclear ribosomal DNA (ITS) ofParmotrema perlatumfrom Europe and Africa (20 of which were newly generated), and 11 ofParmotrema crinitumfrom Europe, North America and North Africa (two newly generated). Additionally, 28 sequences of several species fromParmotremawere included in the ITS dataset. The ITS data matrix was analyzed using different approaches, such as traditional phylogeny (maximum likelihood and Bayesian analyses), genetic distances, automatic barcode gap discovery (ABGD) and the coalescent-based method poisson tree processes (PTP), in order to test congruence among results. Our results indicate that all samples referred toP. crinitumandP. perlatumnested in a well-supported monophyletic clade, but phylogenetic relationships among them remain unresolved. Delimitations inferred from PTP, ABGD and genetic distance analyses were comparable and suggested thatP. crinitumandP. perlatumbelong to the same lineage. Interestingly, two samples ofP. perlatumseparate in a different monophyletic clade, which is supported as a different lineage by all the analyses.