Morphological data, molecular data, and total evidence in phylogenetic analysis

Abstract

Two data sets, one morphological and one molecular, for ascolocular fungi have been analysed separately for taxonomic congruence and in combination for total evidence. Data were analysed with cladistic parsimony, the total support test, and the congruence test. The morphological data set comprised 15 characters and four species, Arthonia radiata, Dendrographa leucophaea, Lecanactis abietina, and Schismatomma pericleum (Arthoniales). The molecular data include the same species and comprised sequence data with 21 informative sites from approximately half of the 18S ribosomal RNA gene. The morphological phylogeny is corroborated by the molecular phylogeny with regard to relationships of Arthonia radiata, Schismatomma pericleum, and Dendrographa leucophaea. But in the molecular phylogeny Lecanactis abietina is placed as a sister species to the former three species. In the phylogeny inferred from morphological data Lecanactis abietina and Dendrographa leucophaea constitute a sister pair with Schismatomma pericleum followed by Arthonia radiata as subsequent sister taxa. The consensus obtained from the taxonomic congruence method was fully collapsed and uninformative. The combined morphological and molecular data in total evidence produced one most parsimonious cladogram. In total evidence Lecanactis abietina is placed as sister species to Schismatomma pericleum and Dendrographa leucophaea all with Arthonia radiata as sister species. The most resolved and phylogenetically informative hypothesis was obtained from cladistic parsimony analysis using total evidence. A review of congruence between morphological and molecular data in determining gross relationships within the Eumycota and Ascomycetes is also given. Key words: Ascomycetes, Arthoniales, phylogeny, cladistics, taxonomic congruence, total evidence, 18SrDNA.