Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2003
Publication Date: N/A
Technical Abstract: Species of the filamentous ascomycete genus Morchella, better known as the true morels or morel `mushrooms', are among the most highly-prized macrofungi collected by mycophiles during Spring in the northern hemisphere. Field guides to morels typically recognize 6 or fewer morphospecies and these are generally assumed to be cosmopolitan in their distribution. To test these hypotheses, multigene genealogies were constructed from a global collection of approximately 600 individuals to investigate the phylogeny and biogeography of Morchella, using a genealogical concordance version of phylogenetic species recognition. Early in the study, allelic variation within the nuclear rDNA internal transcribed spacer region was used as a genetic screen for the detection of putative phylogenetically distinct species. Parsimony analysis of the combined multilocus DNA sequence data provided a nearly fully resolved phylogeny in which a monophyletic Morchella comprised two sister clades: the `yellow-tan-grey' morels (Esculenta clade) and the `black' morels (Elata clade) with 13 and 15 species, respectively. Biogeographical interpretation of the phylogenetic data suggests that the ancestral area for Morchella is North America, the most phylogenetically diverse area studied with 13 endemics [4 Esculenta clade, 9 Elata clade]. The most surprising result of this study is that at least 24 of the 28 species exhibit continental endemism. Results of this study have practical implication for morel breeding and conservation biology and provide a robust phylogenetic framework for studying the evolution of mating systems.