Show simple item record

SYSTEMATICS OF THE GENUS COSMOSPORA (NECTRIACEAE, HYPOCREALES), AND COSPECIATION OF COSMOSPORA SPECIES WITH THEIR ASSOCIATED FUNGAL HOSTS.

dc.contributor.advisorChaverri, Priscilaen_US
dc.contributor.authorHerrera, Cesar Samuelen_US
dc.date.accessioned2014-06-24T06:13:52Z
dc.date.available2014-06-24T06:13:52Z
dc.date.issued2014en_US
dc.identifier.urihttp://hdl.handle.net/1903/15367
dc.description.abstract<italic>Cosmospora</italic> (in the broad sense; Nectriaceae, Hypocreales, Ascomycota) are fungi that parasitize other fungi, particularly fungi in the Xylariales (Ascomycota), or scale insects. Morphologically, these fungi are known for having one of the most simplest and smallest sexual fruiting bodies (<300 &#956;m) among the Nectriaceae. The sexual spores are generally warted. The majority of <italic>Cosmospora</italic> species have acremonium-like or fusarium-like asexual states. The name <italic>Cosmospora</italic> is derived from the ornamentation in the sexual spores (Gr. <italic>cosmos</italic> = ornamented + Gr. <italic>spora</italic> = spore). The main goals of this dissertation were to revise Cosmospora sensu stricto, and to determine the evolutionary relationship between <italic>Cosmospora</italic> species and their associated fungal hosts. Additionally, <italic>Corallomycetella</italic> (Nectriaceae, Hypocreales, Ascomycota), a lineage basal to <italic>Cosmospora</italic> sensu lato, was revised as well. Molecular and classical taxonomic tools were used to revise the genera. A genus was recognized if the clade met the following criteria: 1) the clade was well supported, 2) the clade was associated with a unique asexual state, and 3) the clade was ecologically different. A species was recognized if the clade met the following criteria: 1) the clade was well supported in the majority of single gene trees, 2) the clade was morphologically different, and/or 3) the clade was ecologically different in regards to host. <italic>Cosmospora</italic> species were observed to be highly host specific. Thus, host was recognized as an important character to delineate species, and the host specificity led us to hypothesize that <italic>Cosmospora</italic> species and their associated hosts were cospeciation (i.e., their association was not random). Two new genera, nine new combinations, and eleven new species were described in the taxonomic work included in this dissertation. A significant global congruence was determined between the <italic>Cosmospora</italic> and host phylogenies. However, host-switch events seemed more abundant in the early lineages of the host, while cospeciation events seemed more common in more recent lineages of the host. This phylogenetic signature is consistent with pseudocospeciation, but it could not be confirmed given that divergence estimates could not be estimated.en_US
dc.language.isoenen_US
dc.titleSYSTEMATICS OF THE GENUS COSMOSPORA (NECTRIACEAE, HYPOCREALES), AND COSPECIATION OF COSMOSPORA SPECIES WITH THEIR ASSOCIATED FUNGAL HOSTS.en_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentPlant Science and Landscape Architecture (PLSA)en_US
dc.subject.pqcontrolledSystematic biologyen_US
dc.subject.pqcontrolledMolecular biologyen_US
dc.subject.pquncontrolledCospeciationen_US
dc.subject.pquncontrolledMycoparasiteen_US
dc.subject.pquncontrolledNectriaen_US
dc.subject.pquncontrolledNew generaen_US
dc.subject.pquncontrolledNew speciesen_US
dc.subject.pquncontrolledPhylogeneticsen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record