The Gyromitra gigas species complex includes six morphologically similar taxa, several of which have a long history of segregation, synonymization, and rearrangement among different genera. These taxa occur throughout Asia, Europe, and North America and include G. gigas, G. khanspurensis, G. korfii, G. montana, G. pseudogigas, and G. ticiniana. ITS and LSU sequences from 66 specimens, including type specimens for all six taxa, were included in phylogenetic analyses to establish species boundaries and resolve species relationships. Sequence similarity comparisons were also conducted between the two molecular markers and between the ITS1 and ITS2 regions. Although ITS exhibited sufficient variability to discriminate among species in the G. gigas species complex, LSU displayed very low variability rendering it completely useless as a molecular marker for separating taxa in this group. The ITS1 region was twice as informative as the ITS2 region and can be used as a barcode marker to identify these species. Gyromitra gigas and G. montana occur as a well-supported clade of sister species and can be distinguished based on ascospore morphology. Gyromitra korfii and G. ticiniana also form a highly supported clade and are considered distinct species based on geography. Gyromitra littiniana is confirmed to be synonymous with G. ticiniana based on molecular data. Gyromitra khanspurensis and G. pseudogigas, which also form a highly supported clade, are considered separate species early in the process of speciation that differ significantly in ascomata and ascospore morphology. A key to species based on morphology and geography is provided.
- Holotype barcoding
- ITS sequences
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Agricultural and Biological Sciences (miscellaneous)