Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina

dc.contributor.advisorVerboom, Tonyen_ZA
dc.contributor.authorMusker, Sethen_ZA
dc.date.accessioned2015-09-15T10:32:54Z
dc.date.available2015-09-15T10:32:54Z
dc.date.issued2013en_ZA
dc.description.abstractEhrharta calycina J. E. Sm. (Poaceae) is a widespread and often abundant species whose core distribution lies within the Greater Cape Floristic Region (GCFR). Importantly, it shows a high degree of morphological and ploidy level variation. Based on observations of distinct forms co-occurring at multiple sites, the hypothesis that E. calycina comprises more than one species was tested. Morphological analysis of herbarium specimens using a multivariate approach found strong evidence for the presence of two distinct phenetic clusters among specimens from sites of sympatry, and these were termed ‘robust’ and ‘slender’ forms. This translated to a broader sampling of specimens from across the GCFR (n = 516), of which over 91% could be attributed to one or other form with >90% confidence using linear discriminant analysis. Importantly, chromosome counts supported the hypothesis that these phenetic clusters represent distinct cytotypes, with slender forms being diploid (n = 12) and robust forms tetraploid (n = 24), thus providing the primary reproductive isolating mechanism between the forms. Furthermore, differences in climatic niche suggest that these forms represent ecologically independent entities. Finally, evidence that the forms differ in palatability has considerable practical implications given that E. calycina is regarded as having high pasture value. Together, our results provide multiple lines of evidence for the existence of at least two morphologically distinct, reproductively isolated species within E. calycina, and suggest that the role of polyploidy in generating floral diversity in the GCFR may be more important than previously thought.en_ZA
dc.identifier.apacitationMusker, S. (2013). <i>Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/14016en_ZA
dc.identifier.chicagocitationMusker, Seth. <i>"Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013. http://hdl.handle.net/11427/14016en_ZA
dc.identifier.citationMusker, S. 2013. Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Musker, Seth AB - Ehrharta calycina J. E. Sm. (Poaceae) is a widespread and often abundant species whose core distribution lies within the Greater Cape Floristic Region (GCFR). Importantly, it shows a high degree of morphological and ploidy level variation. Based on observations of distinct forms co-occurring at multiple sites, the hypothesis that E. calycina comprises more than one species was tested. Morphological analysis of herbarium specimens using a multivariate approach found strong evidence for the presence of two distinct phenetic clusters among specimens from sites of sympatry, and these were termed ‘robust’ and ‘slender’ forms. This translated to a broader sampling of specimens from across the GCFR (n = 516), of which over 91% could be attributed to one or other form with >90% confidence using linear discriminant analysis. Importantly, chromosome counts supported the hypothesis that these phenetic clusters represent distinct cytotypes, with slender forms being diploid (n = 12) and robust forms tetraploid (n = 24), thus providing the primary reproductive isolating mechanism between the forms. Furthermore, differences in climatic niche suggest that these forms represent ecologically independent entities. Finally, evidence that the forms differ in palatability has considerable practical implications given that E. calycina is regarded as having high pasture value. Together, our results provide multiple lines of evidence for the existence of at least two morphologically distinct, reproductively isolated species within E. calycina, and suggest that the role of polyploidy in generating floral diversity in the GCFR may be more important than previously thought. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina TI - Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina UR - http://hdl.handle.net/11427/14016 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14016
dc.identifier.vancouvercitationMusker S. Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/14016en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherBiological Sciencesen_ZA
dc.titlePolyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycinaen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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