DISSERTATION RESEARCH: Systematics and Biogeography of the Genus Hysterangium (Basidiomycota, Phallales)

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A grant has been awarded to Dr. Joseph Spatafora and Mr. Kentaro Hosaka at Oregon State University to conduct the study "Systematics and biogeography of the genus Hysterangium". Hysterangium is a genus of mushroom-forming fungi that produces fruiting bodies below ground. Unlike many of the above ground mushrooms, which can disperse their spores by wind, Hysterangium's spores are only dispersed when consumed by animals and deposited with their feces. This fact implies that long distance (e.g., intercontinental) dispersal of Hysterangium is improbable. The distribution of Hysterangium, however, is worldwide. This can be explained by the hypothesis that Hysterangium is a rather ancient organism and its present distribution was caused by the breakup of the supercontinent Pangaea. Importantly, Hysterangium forms mycorrhizae (beneficial relationships with the roots) with many different tree species. Because these relationships are specific, Hysterangium and host trees may have cospeciated. The overall goal of this study is to develop robust hypotheses for biogeography and cospeciation of Hysterangium by collecting and analyzing DNA sequences. To achieve this goal, field expeditions to previously underrepresented areas, Papua New Guinea, New Caledonia, and New Zealand, will be conducted with a special emphasis on the Nothofagus (southern beech) forests.Hysterangium is an important component of forest ecosystems. It produces abundant fruiting bodies, and many animals are heavily dependent on such below ground mushrooms in their diet. Also, mycorrhizal relationships of Hysterangium and host trees are mutualistic. Surveying the Hysterangium flora of Nothofagus forests provides a more clear understanding of these ecosystems, which in turn facilitates more proper forest management. Despite the fact that fungi are one of the most diverse groups of organisms on earth, biogeography of fungi is poorly understood. This study will provide more accurate understanding of biogeographic and cospeciation patterns of mycorrhizal fungi with Hysterangium as a model organism.