Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina
dc.contributor.advisor | Verboom, Tony | en_ZA |
dc.contributor.author | Musker, Seth | en_ZA |
dc.date.accessioned | 2015-09-15T10:32:54Z | |
dc.date.available | 2015-09-15T10:32:54Z | |
dc.date.issued | 2013 | en_ZA |
dc.description.abstract | 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. | en_ZA |
dc.identifier.apacitation | Musker, 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/11427/14016 | en_ZA |
dc.identifier.chicagocitation | Musker, 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/11427/14016 | en_ZA |
dc.identifier.citation | Musker, 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.uri | http://hdl.handle.net/11427/14016 | |
dc.identifier.vancouvercitation | Musker 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/11427/14016 | en_ZA |
dc.language.iso | eng | en_ZA |
dc.publisher.department | Department of Biological Sciences | en_ZA |
dc.publisher.faculty | Faculty of Science | en_ZA |
dc.publisher.institution | University of Cape Town | |
dc.subject.other | Biological Sciences | en_ZA |
dc.title | Polyploid speciation in the Greater Cape Floristic Region : species limits within Ehrhara calycina | en_ZA |
dc.type | Bachelor Thesis | |
dc.type.qualificationlevel | Honours | |
dc.type.qualificationname | BSc (Hons) | en_ZA |
uct.type.filetype | Text | |
uct.type.filetype | Image | |
uct.type.publication | Research | en_ZA |
uct.type.resource | Thesis | en_ZA |
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