Phylogenetic relationships of Agaric fungi based on nuclear large subunit ribosomal DNA sequences

Phylogenetic relationships of mushrooms and their relatives within the order Agaricales were addressed using nuclear large subunit ribosomal DNA sequences. Approximately 900 bases of the 5' end of the nucleus-encoded large subunit RNA gene (nLSU-rDNA) were sequenced for 154 selected taxa representing most families within the Agaricales. Several phylogenetic methods were used, including weighted and equally weighted parsimony (MP), maximum likelihood (ML), and distance methods (NJ). The starting tree for branch swapping in the ML analyses was the tree with the highest ML score among previously produced MP and NJ trees. A high degree of consensus was observed between phylogenetic estimates obtained through MP and ML. NJ trees differed according to the distance model that was used, however, all NJ trees still supported most of the same terminal groupings as MP and ML trees. NJ trees were always significantly suboptimal when evaluated against the best MP and ML trees, using both parsimony a...