Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The Cape Floristic Region (CFR) is situated at the southern tip of Africa and possesses a flora that is unique amongst the floras of the rest of the world, both in terms of its incredibly high species richness, and its high levels of endemism. Proteaceae, the family to which Serruria belongs, is widely distributed amongst the landmasses of the southern hemisphere, with its centres of diversity occurring in Australia and southern Africa. Previous molecular and morphological analyses performed on the South African subfamily Proteoideae have shown Serruria, a CFR endemic, to form a well-supported monophyletic group. Based upon the strong monophyly of Serruria, DNA sequence data were collected for 53 of the 55 species from the plastid (rps16 intron, atpB-rbcL intergenic spacer, trnL-F region and psbA-trnH intergenic spacer) and nuclear (internal transcribed spacer region or ITS) genomes in order to investigate evolutionary relationships within the genus. Spatalla taxa were used as the outgroup. Both parsimony and Bayesian analyses were carried out on each of these data sets. The resulting trees were reasonably well resolved. All the Serruria taxa grouped together in a well-supported clade, except for S. f1ava, which emerged well within the Serruria clade in the analyses of the nuclear genome, but outside the clade in the plastid analyses. It was therefore proposed that this taxon represents a hybrid. Apart from this case, there was widespread agreement between the trees reconstructed using data from the two genomes. The plastid and nuclear data were therefore combined in order to analyse the data sets together. The molecular data does not support most of the groupings proposed by previous authors based on morphological data. Additionally, in some cases, multiple representatives of species do not group together. These specimens probably do not represent monophyletic taxa. Current ideas about relationships within Serruria are based predominantly on floral characters, and it is suggested that pollinator pressures have led to plasticity in the floral characters. Consequently, it is evident from this study that relationships within Serruria need to be re-examined in order to determine the patterns of evolution within the genus. / AFRIKAANSE OPSOMMING: Die Kaapse Floristiese Streek is aan die suiderpunt van Afrika geleë, en beskik oor 'n unieke flora relatief tot ander wêreldfloras, beide ten opsigte van die ongelooflike hoë spesie diversiteit en die hoë vlakke van endemisme. Proteaceae, die familie waaraan Serruria behoort, kom wydverspreid tussen die vastelande van die Suidelike Halfrond voor, en het diversiteitsentrums in Australië en suider Afrika. Vorige molekulêre sowel as morfologiese analises wat op die Suid-Afrikaanse subfamilie Proteoideae uitgevoer is, dui aan dat Serruria (wat endemies is tot die Kaapse Floristiese Streek) 'n goed ondersteunde monofiletiese groep is. Gebaseer op die sterk monofilie van Serruria, is DNA-volgorde-data vir 53 van die 55 spesies vanuit die plastied (rps16 intron, atpB-rbcL intergeniese spasie, trnL-F area en psbA-trnH intergeniese spasie) en kern (intern getranskribeerde spasie area, ook ITS genoem) ingewin om die evolusionêre verwantskappe binne die genus te ondersoek. Spatalla is as die buitegroep gebruik. Beide parsimonie en Bayesian analises is op elk van hierdie datastelle uitgevoer. Die resulterende bome het redelike hoë resolusie getroon. AI die Serruria-taxa het in 'n goed ondersteunde klade saam gegroepeer, behalwe vir S. f1ava, wat binne die Serruria klade val vir die kern genoom, maar buite die klade vir die plastied analise. Dit is dus voorgestel dat hierdie taxon as 'n hibried beskou mag word. Behalwe vir hierdie geval, was daar wydverspreide ooreenstemming tussen die bome wat verkry is vanaf data van die twee genome. Die plastied- en kern-data is derhalwe gekombineer om die datastelle saam te kan analiseer. Die molekulêre data ondersteun nie die meerderheid van morfologiese groeperings wat deur verskeie outeurs voorgestel is nie. Verder, in sommige gevalle, groepeer verskillende monsters van dieselfde spesies nie bymekaar nie. Dit is derhalwe voorgestel dat hierdia taxa nie monofileties is nie. Huidige idees omtrent die verwantskappe binne Serruria is grotendeels op blommorfologiese kenmerke gebaseer, en dit word voorgestel dat bestuiwing-druk gelei het tot plastisiteit van die blommorfologiese kenmerke. Verskille tussen die bome wat uit plastied- en kern-data gerekonstrueer is word aan vroeëre hibridisasie gebeure toegeskryf. Op grond van hierdie studie is dit duidelik dat die verhoudings binne Serruria verder ondersoek moet word om die patrone van evolusie binne die genus te bepaal.

Thesis (MScAgric)--Stellenbosch University, 1994. / Some digitised pages may appear illegible due to the condition of the Microfiche / ENGLISH ABSTRACT: Many Proreaceae species indigenous to South Africa have potential as cutflower crops. Commercial production of proteas for expurt, mainly to Europe, must emphasise quality of flowers and time of production. Good export quality flowers have stems longer than 50cm and unblemished flowers. Cut-flower proteas are in greater demand and command better prices during the European winter (September to May, Southern hemisphere), when competition from flowers grown in Europe is less. Both quality and time of harvest can be manipulated by pruning techniques. Protea cv. Carnival (a natural hybrid, possibly between P. neriifolia and P. compacta) produces flowers in late summer, from February through to May. Picking flowers or pruning shoots of Proteo cv. Carnival entails removing the terminal portion of shoots with heading cuts to leave on the plant short stumps, known as bearers. Lateral shoots arising from axillary buds on bearers elongate by successive growth flushes until flowers are initiated terminally. The characteristics of the shoot determine whether or not flower initiation will take place, and will affect the quality of the resulting flower. Plants were pruned to produce bearers of different length and diameter. The characteristics of shoots arising from different bearers were recordea. Thick bearers of length 20-25cm produced the most shoots, and the longest shoots. Plants producing flowers biennially, rather than ann'Jally, produced thicker bearers, which, in turn, lead to production of better quality shoots arising from the bearers in the following season. Changing the time of pruning changed both the flowering cycle and the biomass allocation of Prorea cv. Carnival. Plants of Profea cv. Carnival were pruned on six different dates in 1991. Pruning in March, April or May, 1991, resulted in an annual flowering cycle. Less than 40% of the fresh mass produced in 1993 was reproductive, of which approximately 5% had stems long enough for export. The 1994 annual harvest was of s:milar size and quality as the 1993 annual harvest. Pruning in July, August or September, 1991, resulted in a biennial cycle of flowering. No flowers were produced in 1992, and a large crop was harvested in 1993. In 1993 lip to 70% of the fresh mass produced was reproductive, of which approximately 80% had stems long enough for export. Plants were pruned shortly after flowering in 1993, and the biennial cycle was replaced by an alternate flowering cycle, with a large crop being followed by a smaller crop. The large harvest in 1993 was significantly earlier than normal, but the small crop produced in 1994 was later. The harvest in 1994 from plants with an alternate flowering cycle was similar in size to the 1994 harvest from plants floweting annually, but flower stems were longer. / AFRIKAANSE OPSOMMING: Heelwat inheemse Proteaceae spesies besit die vereiste eienskappe om as snyblomr.-le verhanctci te wod. Indien proteas kommersieel verbou sou word vir uitvoer moet die klem val op gehalte van blomme en die tyd van produksie. Goeie gehalte uitvoer blomme moet steellengte van langer as 50cm en perfek gevormde blomme besit. Daar is 'n groter aanvraag na kommersieel verboude proteas gedurende die Europese winter (September tot Mei, suidelike halfrond) en beter pryse word derhalwe ook dan verkry. Beide gehalte en die oes periode kan gemanipuleer word deur snoeitegnieke. Wanneer blomme gepluk word of lote gesnoei word van Profea cv. Carnival (waarskynlik 'n kruising tussen P. compacta x P. neriifolia) word die terminale gedeelte van die loot teruggesny. Die oorblywende gedeelte bestaan uit kort stompe wat bekend staan as draers. Laterale lote afkomstig van okselknoppe op draers verleng totdat 'n blom terminaal ontwikkel. Die eienskappe van die loot bepaal of 'n blom inisieer sal word of nie, en sal ook die gehalte van die gevormde blom beinvloed. Protea plante was gesnoei om draers van verkillende lengtes en deursnee te produseer. Die eienkappe van lote afkomstig van die verskillende tipe draers was gemeet. Dik ..draers van lengte 20-25cm het die meeste asook die langste lote geproduseer. Plante wat twee-jaarliks, in teenstelling met jaarliks, geblom het, het dikker draers geproduseer en ook gelei tot produksie van beter gehalte lote in die opeenvolgende seisoen. Die verandering in die tyd van snoei het beide die blom siklus en die biomassa verspreiding beinvloed. Plante van Protea cv. Carnival was up 6 verskillende datums in 1991 gesnoei. Snoei in Maart, April of Mei, 1991, het 'n jaarlikse blom siklus veroorsaak. Minder as 40% van die vars massa geproduseer in 1993 was reproduktief, waarvan 5% steellengte lank genoeg vir uitvoer gehad hel. Die 1994 jaarlikse oes was van dieselfde grootte en gehalte as die van 1993. Snoei in Julie, Augustus of September, 1991, het egter 'n twee-jaarlikse blom siklus veroorsaak. Geen blomme was in 1992 geproduseer nie, maar die oes in 1993 was heelwat groter as die jaarlikse oeste. In 1993 was to 70% van die vars massa geproduseer, reproduktief, waarvan 80% steellengte lank genoeg vir uitvoer gehad het. Die twee-jaarlikse blom siklus het 'n vroeer oes in 1993 veroorsaak, maar 'n later oes in 1994. Die twee-jaarlikse oes in 1994 was van dieseifde grootte as die jaarlikse oes in 1994, maar die blomstele was langer.

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