A phylogenetic study of some representatives of the genus Pentaschistis
| dc.contributor.advisor | Spies, J. J. | |
| dc.contributor.author | Holder, Francisca | |
| dc.date.accessioned | 2017-04-24T09:21:00Z | |
| dc.date.available | 2017-04-24T09:21:00Z | |
| dc.date.issued | 1999-05 | |
| dc.description.abstract | English: The genus Pentaschistis (Nees) Spach consists of 68 species and is endemic to Africa, with 57 species being indigenous to South Africa and 40 species endemic (Gibbs RusseIl et al. 1990). To date, the chromosome number of 30 species have been reported, as well as the sequences of the rpoC2 gene of two species and the ITS region of one species. In this study, seventeen specimens were cytogenetically examined. The polyploid levels ranged from diploid (n = x = 7) to 14-ploid (n = 7x = 49). Two species were examined for the first time, namely: P. capensis (diploid) and P. veneta (tetraploid). New polyploid levels were also observed for P. viscidula (tetraploidy), P. densifolia (octaploidy), P. rupestris (decaploidy & 14-ploidy) and P. tortuosa (octaploidy). Due to the fact that no, or very few, multivalents were observed, we concluded that the species are alloploids or segmental alloploids tending towards alloploidy. The morphological groupings (Linder & Ellis 1990a) could unfortunately neither be supported nor rejected by cytogenetic evidence alone, therefore cytogenetics was used in conjunction with molecular data to determine the phylogeny. The fragment patterns obtained from RAPDs were used to calculate the genetic distances. A high degree of variation was observed within and between the morphological groups. Cladograms were obtained with the computer programs PAUP and Hennig86, and PAUP gave the most parsimonious cladogram. The resolutions of these cladograms were, however, not good, therefore DAFs was performed. Again PAUP and Hennig86 were used and again PAUP proved to give the most parsimonious clado gram. These cladograms gave a clearer indication of the phylogeny of Pentaschistis, but the genetic distances within and between the species again proved to be high. The ITS} region was sequenced and aligned separately with Clustal W and Malign. These cladograms indicated a close alliance between P. eriostoma and P. curvifolia. The three data sets were combined and a cladogram with much better resolution was obtained. The morphological data was included and had a minor influence on the phylogeny. This cladogram also indicated a sister relationship between P. eriostoma and P. curvifolia. Current data suggest that P. eriostoma could well have developed through the hybridisation of P. curvifolia and that both P. eriostoma are correctly grouped with Pentaschistis. The combined analysis also indicate that the morphological groupings of Linder & Ellis (1990a) is somewhat supported by phylogeny. | en_ZA |
| dc.description.abstract | Afrikaans: Die genus Pentaschistis (Nees) Spach bestaan uit 68 spesies, waarvan 57 inheems en 40 endemies tot Suid-Afika is (Gibbs Russell et al. 1990). Die chromosoomgetalle van 30 spesies is tot dusver gepubliseer, sowel as die nukleotiedvolgordes van die rpotl, geen van twee spesies en die nukleotiedvolgorde van die ITS gebied van een spesie. In hierdie studie is 17 eksemplare sitogeneties ondersoek. Die poliploïede vlakke het gevarieer van 'n diploïd (n = x = 7) tot 'n 14-ploïed (n = 7x = 49). Twee spesies is vir die eerste keer sitogeneties ondersoek, naamlik P. capensis (diploïed) en P. veneta (tetraploïed). Nuwe poliploïede vlakke is ook waargeneem vir P. visciduia (tetraploïed), P. densifolia (oktaploïed), P. rupestris (dekaploïed & 14-ploïed) en P. tortuosa (oktaploïed). Omdat min of geen multivalente waargeneem is nie, kan aanvaar word dat die spesies alloploïede of segmenteie alloploïede is, wat neig tot allopoïede. Die sitogenetiese data alleen kon nie die morfologiese groeperings van Linder & Ellis (1990a) ondersteun nie. Daarom word sitogenetika in samewerking met molekulêre data gebruik om die filogenie te bepaal. Die fragmentpatrone verkry vanaf RAPD data is gebruik om die genetiese afstande te bereken. 'n Hoë mate van variasie is binne en tussen die morfologiese groepe waargeneem. Beide PAUP and Hennig86 is gebruik om kladogramme te verkry en PAUP het die mees parsinomiese kladogram verskaf. Die resolusie van hierdie bome was egter nie baie goed nie, daarom is daar ook van DAFs gebruik gemaak. Beide PAUP en Hennig86 is gebruik en weereens het PAUP die mees parsinomiese kladogramme verskaf. Hierdie kladogramme het 'n beter indikasie van die filogenie van Pentaschistis gegee, maar die genetiese afstande binne en tussen die spesies was weereens hoog. Die nukleotiedvolgorde van die ITS] gebied is bepaal en inlyn gestel met onderskeidelik Clustal W en Malign. Kladogramme verkry vanaf hierdie data het 'n noue verwantskap tussen P. eriostoma en P.curvifolia aangedui. Al drie datastelle is gekombineer en 'n kladogram met 'n beter resolusie is verkry. Morfologiese data is ingesluit en het 'n geringe invloed op die filogenie gehad. Hierdie kladogram het aangetoon dat P. eriostoma en P. curvifolia naverwant is. Data verkry tydens hierdie studie stel voor dat die verbastering van P. curvifolia wel tot die ontwikkeling van P. eriostoma kon gelei het, en dat P. eriostoma korrek binne Pentaschistis gegroepeer is. Volgens die gekombineerde data vorm die morfologiese groeperings van Linder & Ellis (1990a) wel 'n basis vir filogenetiese studies. | af |
| dc.description.sponsorship | Foundation for Research Development | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/6135 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Arundineae | en_ZA |
| dc.subject | Arundinoideae | en_ZA |
| dc.subject | Cytogenetics | en_ZA |
| dc.subject | DNA amplification fingerprinting (DAFs) | en_ZA |
| dc.subject | Pentaschistis | en_ZA |
| dc.subject | Poaceae | en_ZA |
| dc.subject | Polyploidy | en_ZA |
| dc.subject | Internal transcribed spaeers (lTS) | en_ZA |
| dc.subject | Random amplified polymorphic DNA (RAPDs) | en_ZA |
| dc.subject | Sequencing | en_ZA |
| dc.subject | Pentaschistis -- Phylogeny | en_ZA |
| dc.subject | Grasses -- Phylogeny | en_ZA |
| dc.subject | Dissertation (M.Sc. (Botany and Genetics))--University of the Free State, 1999 | en_ZA |
| dc.title | A phylogenetic study of some representatives of the genus Pentaschistis | en_ZA |
| dc.type | Dissertation | en_ZA |