Item – Theses Canada

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OCLC number
903768784
Link(s) to full text
LAC copy
LAC copy
Author
McDevit, Daniel Christopher,1979-
Title
A molecular assisted survey and phylogenetic study of Canadian brown macroalgae (Phaeophyceae).
Degree
Ph. D. -- University of New Brunswick, 2010
Publisher
Ottawa : Library and Archives Canada = Bibliothèque et Archives Canada, [2013]
©2010
Description
3 microfiches
Notes
Includes bibliographical references.
Abstract
<?Pub Inc> Despite numerous studies, species biodiversity and phylogenetic relationships in brown macroalgae (Phaeophyceae) are poorly understood. Morphological plasticity and convergent evolution, combined with a lack of diagnostic features, can make species level identifications within the Phaeophyceae difficult, even under the best of conditions, in part explaining this gap in knowledge. This thesis is part of a larger initiative, termed DNA barcoding, to study global biodiversity (in seaweeds, as well as in other organisms) using molecular tools. The concept of a DNA barcode is to use a short, standardized marker, such as the 5' end of cytochrome c oxidase 1 (COI-5P) - a mitochondrial gene, for species identification across a broad range of taxa. In this study, the utility of COI-5P for species-level differentiation was tested in brown macroalgae and was found to differentiate closely related species. Using newly developed DNA extraction techniques, the COI-5P barcode was used to conduct a floristic survey of two groups of brown algae in Canada, the Laminariales and the Scytosiphonaceae. For the Laminariales, a species thought to be absent from the Atlantic, 'Saccharina groenlandica', was revealed to have a much broader distribution. With its varying morphologies, it was found to resemble superficially two common kelps, 'Laminaria digitata ' and 'Saccharina latissima'. In addition, COI-5P divergence within 'S. latissima' allowed for the generation of a biogeographical model for this species. For the Scytosiphonaceae, substantial levels of molecular variation pointed to the existence of a number of overlooked species. The Canadian flora is dominated by three newly described species of 'Scytosiphon, S. compressus, S. cylindricus' and 'S. promiscuus'. The two species of 'Scytosiphon' reported to be present in North America, 'S. dotyi' and 'S. lomentaria', are either absent or rare in Canada, respectively. Finally, a combined ' rbc'L/'psa'A phylogeny of the Scytosiphonaceae supports the transfer of 'Colpomenia bullosa, Endarachne binghamiae' and species of the genera 'Melanosiphon, Myelophycus and Petalonia ' to 'Scytosiphon'.
ISBN
9780494876787
0494876786