The phylogenetic relationship in the Lachenalia pusilla group
| dc.contributor.advisor | Spies, P. | |
| dc.contributor.advisor | Spies, J. J. | |
| dc.contributor.author | Londoloza, Sizane Bulelani | |
| dc.date.accessioned | 2015-11-10T12:54:12Z | |
| dc.date.available | 2015-11-10T12:54:12Z | |
| dc.date.copyright | 2014-07 | |
| dc.date.issued | 2014-07 | |
| dc.date.submitted | 2014-07 | |
| dc.description.abstract | English: The geophytic genus Lachenalia Jacq.f.ex Murray is the largest genus (consists about 133 species, Duncan (2012)) in the tribe Massonieae. It is the most complex and advanced genus within the tribe Massonieae (sub-‐family Hyacinthoideae) (Pfosser et al. 2003). This highly morphological and chromosomal variable genus, is endemic to the south-‐western winter rainfall regions of Southern Africa with few exceptions and has been recorded in the literature as early as the 17th century (1787 Jacquin). The genus Lachenalia has commercial value as a garden pot plant or for cut flowers. From as early as the 1990s, the ARC started a breeding programme with the aims to improve and increase the international market potential of this plant. There is a correlation between species’ basic chromosome number, molecular systematics and cross-‐ability, thus (1) based on molecular systematics, species with the same basic chromosome number group together on the phylogenetic tree and (2) species in the same group have higher cross-‐ability. Several authors revised the classification and grouping of Lachenalia species. However, the inventory of the species and species delimitation is not yet complete. Frequently, different species within the genus Lachenalia are treated under the same name (species can be mis-‐identified and then recognised as a different species, i.e., L. pallida) or one plant is distributed between different names (i.e. L. pallida). This error results in a highly heterogeneous and polymorphic genus that forms polymers or high homoplastic phylogenetic trees. Species with x = 7 are ancestral species from which other species evolved. T 80 The evolutional relationship of x = 9, 10 and 13 species, plus x = 7 and 8 prostrate and geoflora like species (Lachenalia pusilla group) was tested using molecular phylogenetic markers (ITS, rbcL, trnL-‐F and psbA-‐trnH). Species with x = 7 (group x = 7), x = 8 (group x = 8), x = 11 (group x = 11) and subspecies Polyxena (Polyxena group) formed monophyletic clades. The majority species from the Lachenalia pusilla group are scattered between the other groups. The Lachenalia pusilla group may be a hybridization product of Lachenalia species with different basic numbers, and/or with their closest Lachenalia relative (possibly with the genus Massonia). Incongruence test performed on two BI trees of the plastid dataset (trnL-‐F) and nucleus dataset (ITS2) (Tanglegram) suggested a hybrid evolution of the Lachenalia pusilla group. Evolution of the Lachenalia pusilla group (species with x = 9, 10 and 13) plus certain x = 7 and x = 8 species by means of hybridization was also supported by reticulate analyse (NJ tree). This study suggested a reticulate evolution of the Lachenalia pusilla group (x = 9, 10 and 13) and few taxon with x = 7 and 8. Previous studies recommended multiple gene phylogenetic analysis for better Lachenalia species resolution. However, due to high incongruence between datasets, multiple gene analysis does not provide better answers for Lachenalia classification. Genomic in situ hybridization, reticulate analysis and other phylogenetic methods can results in better species delimitation of Lachenalia. | en_ZA |
| dc.description.abstract | Afrikaans: Die geofietiese genus Lachenalia Jacq.f.ex Murray is die grootste genus (bestaan Uit ngeveer 133 spesies, Duncan (2012) in die stam Massonieae. Dit is die mees komplekse en gevorderde genus binne die stam Massonieae (Hyacinthoideae sub-‐familie) (Pfosser et al. 2003). Hierdie genus wat mofologiese en chromosomal hoogs varierend is, is meestal endemies aan die suid-‐westerlike winterreenvalstreek van Suid-‐Afrika (met 'n paar uitsonderings) en is reeds vroeg (1787 Jacquin) in die literatuur aangeteken. Die genus Lachenalia het kommersiele waarde as 'n tuin plant, pot plant of snyblomme. So vroeg as die 1990's het die ARC met 'n teelprogram begin met die doelwit om die plante te verbeter en die internasionale markpotensiaal van hierdie plant verhoog. Daar is 'n korrelasie tussen spesies se basiese chromosoomgetal, molekulere sistematiek en kruis-‐ vermoe, dus (1) spesies met dieselfde basiese chromosoomgetal groepeer saam op die filogenetiese boom (2) spesies in dieselfde groep het 'n hoe kruis-‐vermoe. Verskeie outeurs het die klassifikasie en groepering van Lachenalia spesies hersien. Maar die indeling van die spesies en spesies afbakening is nog nie voltooi nie. Dikwels word verskillende spesies in die genus Lachenalia onder dieselfde naam beskryf (spesies kan verkeerdelik geidentifiseer word en as ‘n verkeerde spesie benaam word soos in die geval van L. pallida). Hierdie problem het 'n hoogs heterogene en polimorfiese genus tot gevolg wat polimere of ‘n groot mate van homoplastiese filogenetiese bome tot gevolg het. Spesies met x = 7 is die voorvaderlike spesies waaruit ander spesies ontwikkel het. Ons het met behulp van molekulere filogenetiese merkers (ITS, rbcL, trnL--‐F en psbA--‐ trnH) die evolusionere verwantskap tussen spesies met x = 9, 10 en 13 getoets, insluitend spesies met x = 7 en 8, wat die uitgestrekte en laag-‐groeiende spesies (Lachenalia pusilla groep) bevat. Spesies met x =7 (groep x = 7), x = 8 (groep x = 8), x = 11 (groep x = 11) en subspecies Polyxena (Polyxena groep) het monofiletiese groepe gevorm. Die meerderheid spesies van die Lachenalia pusilla groep is tussen die ander groepe versprei. Dit wil voorkom of die Polyxena groep 'n gemengde produk tussen Lachenalia spesies en die naverwante genus (moontlik die genus Massonia) is. Die inkongruensietoets wat op twee BI bome van die plastied datastel (trnL--‐F) en kern datastel (ITS2) (Tanglegram) uitgevoer is, suggereer ‘n moontlike baster evolusie van die Lachenalia pusilla groep. Evolusie van die Lachenalia pusilla groep (spesies met x = 9, 10 en 13) tesame met sekere x = 7 en x = 8 spesies, weens verbastering word ook deur die retikulasie-‐analise (NJ boom) ondersteun. Hierdie studie suggereer dat daar retikulere evolusie van die Lachenalia pusilla groep (x = 9, 10 en 13) en 'n paar takson met x = 7 en 8 plaasgevind het. Vorige studies stel voor dat veelvuldige gene vir die filogenetiese analise gebruik moet word om sodoende 'n beter resolusie vir die genus Lachenalia te verseker. Maar as gevolg van die hoe mate van onverenigbaarheid tussen datastelle, verskaf die analisering van veelvuldige gene nie beter antwoorde vir die klassifikasie van Lachenalia nie. Genomiese in situ verbastering, network analise en ander filogenetiese metodes kan lei tot beter spesies afbakening van Lachenalia. | af |
| dc.identifier.uri | http://hdl.handle.net/11660/1588 | |
| 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 | Reticulate evolution | en_ZA |
| dc.subject | Phylogenetic relationship | en_ZA |
| dc.subject | Phenotypic plasticity | en_ZA |
| dc.subject | Massonia | en_ZA |
| dc.subject | Lachenalia pusilla group | en_ZA |
| dc.subject | Lachenalia | en_ZA |
| dc.subject | Basic chromosome number | en_ZA |
| dc.subject | GISH | en_ZA |
| dc.subject | Incongruence test | en_ZA |
| dc.subject | Dissertation (M.Sc. (Genetics))--University of the Free State, 2014 | en_ZA |
| dc.title | The phylogenetic relationship in the Lachenalia pusilla group | en_ZA |
| dc.type | Dissertation | en_ZA |