Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Andrew S. Methven


As part of a biosystematic study of the Lentinellus ursinus species complex, field and herbarium specimens from North America, Central America, and Europe were examined. Single basidiospore isolates from basidiomata collected in Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Tennessee, North Carolina, Wisconsin, Costa Rica, and Austria were crossed in all possible combinations to determine the mating system operating in each population. All populations exhibited bifactorial or tetrapolar mating systems. Tester strains were then crossed to identify intercompatible populations and to determine if morphological species in the L. ursinus species complex are congruent with biological species. Three biological species were recognized and identified as L. ursinus, L. angustifolius, and L. vulpinus. Polyspore isolates were subsequently used in culture mat and phenoloxidase analyses to facilitate identification of somatic cultures. The production of gloeocystidia and/or chlamydospores is taxonomically important for identifying somatic cultures of these species. All three taxa produced laccase, tyrosinase, and peroxidase in culture and were identified as white-rot fungi. This represents the first confirmed report of L. angustifolius from North America.