This dissertation presents the results of studies of the generic concept of Senecio and the subsequent testing of the hypothes is: that many of the species of Senecio in Natal are congeneric with Senecio L. sensu stricto. The sample of taxa studied consisted of 87 Natal senecios, 5 Cape heterochromous senecios and 10 non-southern African senecios, including the type of the genus, S. vulgaris L. Also included in the study were 5 species from taxonomically closely related genera in the tribe Senecioneae and two senecios of uncertain taxonomic position. The phenotype of these taxa was investigated with respect to a large number of morphological and micromorphological characters (126) and the data obtained were analysed neurally and numerically. Aspects of the pollen micromorphology, of all the taxa studied, were also investigated using the scanning electron microscope. A review of the chemical complement of all the taxa studied. particularly with respect to terpenes and pyrrolizidine alkaloids, was also undertaken. Six characters were selected as being taxonomically significant with respect to elucidating the generic concept of Senecio. A further 31 characters and the aforementioned 6, were selected as .being taxonomically significant with respect to elucidating the interrelationships of the Natal senecios and all the senecios studied. The generic concept of Senecio has been re-circumscribed and the generic status of each of the senecios studied has been tested according to this concept of Senecio sensu Vincent. In the light of my concept of Senecio, the following species are excluded from Senecio sensu Vincent: S. barbertonicus Klatt, S. cissampelinus (DC.) Schultz Bipontinus, S. fulgens (J.D. Hooker) Nicholson, S. helminthioides (Schultz Bipontinus) Hilliard, S. hockii De Wild. & Muschl., S. medley-woodii Hutchinson, S. radicans (L.L) Schultz Bipontinus, S. syringifolius O.Hoffm., S. tamoides DC., S. transvaalensis Bolus and S. viminalis Bremekamp. Senecio brevilorus Hilliard, S. seminiveus Wood & Evans and S. tanacetopsis Hilliard are considered to be peripheral to Senecio s. str. sensu Vincent, and are included in Senecio s. lat. sensu Vincent. The hypothesis regarding the generic status of the Natal senecios has been accepted, subsequent to the circumscription of Senecio s. str. sensu Vincent. Estimates of the phenetic affinity of all the members of Senecio sensu stricto sensu Vincent, included in this study, have been made. The majority of the Natal senecios, while clearly being members of Senecio s. str. sensu Vincent, are distinct from virtually all the Cape and non-southern African senecios studied. Many of the non-yellow (purple) Natal senecios form clearly allied groups which are distinct from the groups (clusters) composed of yellow senecios. The taxonomic position of several taxa is questioned, in the light of the cluster analyses. The evidence from the palynological studies neither contradicts nor supports the proposed infrageneric interrelationships, with respect to the Natal members of Senecios. str. sensu Vincent. The evidence also neither contradicts nor supports the proposed interrelationships between the Natal, the Cape and the non-southern African members of Senecios. str. sensu Vincent. The terpene and pyrrolizidine chemistry of many of many of the senecios studied is characterised by the presence of furanoeremophilanes. Eremophilanes also occur and are particularly associated with a number of non-yellow (purple) senecios. Pyrrolizidine alkaloids are not ubiquitous amongst the senecios studied, while some senecios appear to only synthesise pyrrolizidine alKaloids. The review of the errpene and pyrrolizidine chemistry of the senecios investigated, illustrates how our knowledge at or near the level of analytic characters is far from complete. However, we have definitely progressed from the synthetic level of character use. Nevertheless, the relationships between the members of Senecios. str. sensu Vincent, could not be evaluated in the light of the individual chemical complement of terpenes and pyrrolizidine alkaloids, because of a lack of information. An hypothesis of the chemical evolution within the Senecioneae is tested with in Senecios. str. sensu Vincent . Before any taxonomic changes are made to t he current composition of Senecio L., the concept of Senecio L. s. str. sensu Vincent, needs to be tested against a far wider sample of the genus. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1984.

No presente trabalho foram analisados os cariótipos de dez espécies do gênero Mikania utilizando-se a metodologia convencional de Feulgen, o bandamento C e a metodologia de impregnação pela prata (banda NOR). As espécies foram agrupadas por secção encontrando-se para a secção Thyrsigerae: M. additicia com 2n = 34 cromossomos, M. diversifolia, M. hemisphaerica, M. lanuginosa e M. punctata com 2n = 36 cromossomos e M. sericea com 2n =42 cromossomos. Para a secção Corymbosae encontrou-se M. hastato cordata com 2n=34 e M. involucrata com 2n=36 cromossomos. Agrupada na secção Spicato-Racemosae encontrou-se M. sessilifolia um poliploide com 2n = 108 cromossomos. Foi analisada também uma espécie, não identificada botanicamente, com 2n = 34 cromossomos. Todas as espécies estudadas até o momento apresentam o par de cromossomos maior, com uma constrição secundária na porção mediana do braço maior. Através de coloração com nitrato de prata evidenciou-se nesta região, a presença do organizador nucleolar. A análise estatística mostrou que o par de cromossomos maior apresenta variação entre as diferentes espécies, quanto ao seu comprimento absoluto. No entanto, seu padrão morfológico característico permitiu considerá-lo como um marcador citológico para o gênero conforme sugerido em RUAS & RUAS (1987). Apesar das semelhanças encontradas em aspectos gerais de seus cariótipos, as espécies apresentaram diferenças entre cromossomos individuais. Estas diferenças estão relacionadas, principalmente, com pequenas variações, no comprimento absoluto e na posição do centrômetro entre pares de cromossomos correspondentes, o que conferiu características próprias a cada espécie. A análise do grau de assimetria mostrou que todas as espécies apresentam uma tendência à assimetria sendo que, comparativamente, M. hastato cordata foi a mais assimétrica. A coloração, pela metodologia de bandamento C, evidenciou a presença de um único ou poucos cromocentros, em alguns núcleos interfásicos, sem no entanto, detectar bloco heterocromático correspondente em cromossomos metafásicos. Com base na hipótese evolutiva proposta por LAWRENCE (1951) para os tipos de influrescência, que ocorrem em Compositae, foi sugerida para Mikania, a existência de uma relação , entre a alta frequência de espécies com x=18 e tipo de influrescência mais primitiva. A partir desses dados, foi considerada a possibilidade, de que o número básico original para o gênero é x=18, a partir do qual derivaram, por aneuploidia os números x=17, 19, 20 e 21, os quais compõem a série aneuplóide regular constatada até o momento, no gênero. Foi também verificada a ocorrência de espécies poliploides, como M. micranta com 2n = 72, M. viminea com 2n = 68 (RUAS & RUAS, 1987) e M. sessilifolia com 2n= 108 cromossomos. / In the present work the karyotypes of ten species of the genus <iMikania were analyzed using Feulgen's conventional staining, C-banding, and a silver impregnation method (NOR banding). The species were grouped by sections; for the section Thyrsigerae it was found M. additicia with 2n = 34 chromosomes, M. diversifolia ,M. hemisphaerica, M. lanuginosa ,and M. punctata , with 2n = 36, and M. sericea with 2n = 42 chromosomes. In the section Corymbosae, 2n= 34 was found for M. hastato cordata and 2n = 36 chromosomes for M. involucrata. A polyploid with 2n = 108 chromosomes, M. sessilifolia</I, was found in the section Spicato-Racemosae. One species unidentified with 2n = 34 chromosomes was also analyzed. AlI the species studied show a pair of Iarge chromosomes with a secondary constriction in the mid-position of the long arm; staining with siIver nitrate shows the presence of the nucIeolar organizer in that region. Statistic analysis shows that the absolute length of the long chromosomes varies among the different species, however, the characteristic morphology of that pair allows suggests that it can be considered as a cytological marker to the genus as suggested by RUAS & RUAS (1987). In spite of the similarities found in their karyotypes, the species show differences among individual chromosomes. Those differences are mainly related to small variations in the absolute length and position of the centromere between homologous pairs of chromosomes, confering characteristics proper to each species. Analysis of the degree of asymmetry has evidenced that all the species studied have a trend toward asymmetry, M. hastato cordata being the most asymmetrical comparatively. Staining by the C-banding method has shown one or few chromocentres in a some interphasic nuclei, without detecting correspondent heterochromatic blocs in metaphasic chromosomes. According to the evolutive hypothesis proposed by LAWRENCE (1951) for the inflorescence types in Compositae, a relationship between higher frequency of species with x = 18 and the type of more primitive inflorescence was suggested. It was suggested as well, that the basic original number for the genus is which the other numbers found x = 17, 19, 20 and 21 have originated by aneuploidy and form the regular aneuploid series observed at this moment. Polyploid species have also been found, as M. micrantha with 2n = 72, M. viminea with 2n = 68 (RUAS & RUAS, 1987) and M. sessilifolia with 2n = 108 chromosomes.

Not available / text

Thesis (Ph.D.)(Plant production)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

No presente trabalho foram analisados os cariótipos de dez espécies do gênero Mikania utilizando-se a metodologia convencional de Feulgen, o bandamento C e a metodologia de impregnação pela prata (banda NOR). As espécies foram agrupadas por secção encontrando-se para a secção Thyrsigerae: M. additicia com 2n = 34 cromossomos, M. diversifolia, M. hemisphaerica, M. lanuginosa e M. punctata com 2n = 36 cromossomos e M. sericea com 2n =42 cromossomos. Para a secção Corymbosae encontrou-se M. hastato cordata com 2n=34 e M. involucrata com 2n=36 cromossomos. Agrupada na secção Spicato-Racemosae encontrou-se M. sessilifolia um poliploide com 2n = 108 cromossomos. Foi analisada também uma espécie, não identificada botanicamente, com 2n = 34 cromossomos. Todas as espécies estudadas até o momento apresentam o par de cromossomos maior, com uma constrição secundária na porção mediana do braço maior. Através de coloração com nitrato de prata evidenciou-se nesta região, a presença do organizador nucleolar. A análise estatística mostrou que o par de cromossomos maior apresenta variação entre as diferentes espécies, quanto ao seu comprimento absoluto. No entanto, seu padrão morfológico característico permitiu considerá-lo como um marcador citológico para o gênero conforme sugerido em RUAS & RUAS (1987). Apesar das semelhanças encontradas em aspectos gerais de seus cariótipos, as espécies apresentaram diferenças entre cromossomos individuais. Estas diferenças estão relacionadas, principalmente, com pequenas variações, no comprimento absoluto e na posição do centrômetro entre pares de cromossomos correspondentes, o que conferiu características próprias a cada espécie. A análise do grau de assimetria mostrou que todas as espécies apresentam uma tendência à assimetria sendo que, comparativamente, M. hastato cordata foi a mais assimétrica. A coloração, pela metodologia de bandamento C, evidenciou a presença de um único ou poucos cromocentros, em alguns núcleos interfásicos, sem no entanto, detectar bloco heterocromático correspondente em cromossomos metafásicos. Com base na hipótese evolutiva proposta por LAWRENCE (1951) para os tipos de influrescência, que ocorrem em Compositae, foi sugerida para Mikania, a existência de uma relação , entre a alta frequência de espécies com x=18 e tipo de influrescência mais primitiva. A partir desses dados, foi considerada a possibilidade, de que o número básico original para o gênero é x=18, a partir do qual derivaram, por aneuploidia os números x=17, 19, 20 e 21, os quais compõem a série aneuplóide regular constatada até o momento, no gênero. Foi também verificada a ocorrência de espécies poliploides, como M. micranta com 2n = 72, M. viminea com 2n = 68 (RUAS & RUAS, 1987) e M. sessilifolia com 2n= 108 cromossomos. / In the present work the karyotypes of ten species of the genus <iMikania were analyzed using Feulgen's conventional staining, C-banding, and a silver impregnation method (NOR banding). The species were grouped by sections; for the section Thyrsigerae it was found M. additicia with 2n = 34 chromosomes, M. diversifolia ,M. hemisphaerica, M. lanuginosa ,and M. punctata , with 2n = 36, and M. sericea with 2n = 42 chromosomes. In the section Corymbosae, 2n= 34 was found for M. hastato cordata and 2n = 36 chromosomes for M. involucrata. A polyploid with 2n = 108 chromosomes, M. sessilifolia</I, was found in the section Spicato-Racemosae. One species unidentified with 2n = 34 chromosomes was also analyzed. AlI the species studied show a pair of Iarge chromosomes with a secondary constriction in the mid-position of the long arm; staining with siIver nitrate shows the presence of the nucIeolar organizer in that region. Statistic analysis shows that the absolute length of the long chromosomes varies among the different species, however, the characteristic morphology of that pair allows suggests that it can be considered as a cytological marker to the genus as suggested by RUAS & RUAS (1987). In spite of the similarities found in their karyotypes, the species show differences among individual chromosomes. Those differences are mainly related to small variations in the absolute length and position of the centromere between homologous pairs of chromosomes, confering characteristics proper to each species. Analysis of the degree of asymmetry has evidenced that all the species studied have a trend toward asymmetry, M. hastato cordata being the most asymmetrical comparatively. Staining by the C-banding method has shown one or few chromocentres in a some interphasic nuclei, without detecting correspondent heterochromatic blocs in metaphasic chromosomes. According to the evolutive hypothesis proposed by LAWRENCE (1951) for the inflorescence types in Compositae, a relationship between higher frequency of species with x = 18 and the type of more primitive inflorescence was suggested. It was suggested as well, that the basic original number for the genus is which the other numbers found x = 17, 19, 20 and 21 have originated by aneuploidy and form the regular aneuploid series observed at this moment. Polyploid species have also been found, as M. micrantha with 2n = 72, M. viminea with 2n = 68 (RUAS & RUAS, 1987) and M. sessilifolia with 2n = 108 chromosomes.

Made available in DSpace on 2014-06-12T18:02:17Z (GMT). No. of bitstreams: 2 arquivo772_1.pdf: 1868106 bytes, checksum: 78d0318b7da07c04a52a55f655b0ce01 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / A família Asteraceae contém a maior biodiversidade entre as angiospermas, sendo relativamente bem estudada citogeneticamente quanto ao número cromossômico; no entanto, pouco se conhece a respeito das características específicas da cromatina da maioria de seus representantes. Neste contexto, o número diploide, o tamanho cromossômico, o padrão de bandeamento CMA/DAPI e a distribuição de genes ribossomais por FISH foram utilizados em uma análise comparativa de 23 acessos pertencentes a 13 espécies, 11 gêneros, nove tribos e três subfamílias, no intuito de analisar suas relações evolutivas. As alterações cromossômicas encontradas evidenciaram alguns rearranjos cariotípicos. Os sítios de DNAr 45S e 5S variaram em número e localização. Oito padrões de bandeamento CMA/DAPI foram descritos para a heterocromatina: 1) CMA++/DAPI-, colocalizada com sítio de DNAr 45S; 2) CMA+/DAPI-, colocalizada com sítio de DNAr 5S; 3) bandas CMA+/DAPI- terminais; 4) bandas CMA-/DAPI+ terminais; 5) bandas CMA-/DAPI++ terminais; 6) bandas CMA-/DAPI+ pericentroméricas; 7) bandas CMA-/DAPI++ pericentroméricas, e 8) bandas dependentes do padrão de condensação. O gênero Cichorium destacou-se por apresentar variação interespecífica relacionada à diferença no número de sítios de DNAr entre C. endivia e C. intybus. Além disso, um dos acessos de C. intybus mostrou uma variação intraespecífica, com dois pares portadores de DNAr envolvidos em uma provável translocação recíproca. A ampla variabilidade de dados citogenéticos foi informativa, auxiliando no entendimento da evolução, compreendendo caracteres promissores para a classificação sistemática desta família

Plants are an invaluable source of medicinal compounds and their use for healing is rooted in ancient times. Aptosimum procumbens (Scrophulariaceae) and Garuleum bipinnatum (Asteraceae) are two indigenous South African plants that have been used as traditional remedies. Phytochemical investigations were performed with the aim of isolating and identifying compounds that may be responsible for the recorded medicinal properties of these plants. Various chromatographic techniques were utilized for the separation of the plant extract constituents. Several terpenoid compounds were isolated from both plants and the flavanone was isolated from A. procumbens. Nuclear magnetic resonance spectroscopy including 1H NMR, 13C NMR, COSY, DEPT, HMQC, HSCQ, HMBC and NOESY experiments were performed to allow for structure determination, the results of which will be discussed. The iridoid glycosides angeloside, shanzhiside methyl ester, barlerin, a new compound foliamethoylshanzhiside methyl ester and the flavanone pinocembrin neohesperidoside were identified as constituents of A. procumbens. Fractionation of the G. bipinnatum extract afforded several sandaracopimar-15-ene diterpenoid derivatives, namely sandaracopimar-15-ene-8ƒÒ-ol, sandaracopimar-15-ene-8ƒÒ,11ƒÑ-diol, 12-O-acetylsandaracopimar-15-ene-8ƒÒ,11ƒÑ,12ƒÒƒn-triol, 11-O-acetylsandara-copimar-15-ene-8ƒÒ,11ƒÑ,12ƒÒƒn-triol, 11-O- feruoylsandaracopimar-15-ene-8ƒÒ,11ƒÑƒz12ƒÒ-triol and 11-O-p-coumaroylsandaracopimar-15-ene-8,11ƒÑ,12ƒÒ-triol. Diterpenoids are known to possess antimicrobial properties enabling them to fight off various infections and monoterpenoid iridoid glycosides generally have anti-inflammatory properties that make them wound-healing agents. Flavonoids are a diverse group of compounds with enormous structural variations and have a wide range of medicinal properties. A general review on the structural classification, biosynthesis and biological activity of these secondary metabolites is given in this dissertation. Iridoids are commonly found in plants belonging to the Scrophulariaceae family and shanzhiside methyl ester has also been isolated from A. indivisum, a related Aptosimum species. Many plants from the Scrophulariaceae family have been used as traditional medicine to treat wounds. The crude extract of the plant tested positive for antitumor activity against three cell lines, namely melanoma, breast and renal. G. bippinatum belongs to one of the largest plant families, Asteraceae and the crude extract exhibited antimicrobial activity against several microorganisms. / Prof. F.R. van Heerden

Berkheya Ehrh. is a genus of daisies in the tribe Arctotideae, subtribe Gorteriinae with over 80 species, most of which occur in southern Africa. This genus has centres of diversity associated with the montane regions of South Africa, including the Drakensberg Alpine Centre and Mpumalanga escarpment regions. Previous molecular and morphological studies indicate that Berkheya is paraphyletic. I present phylogenies based on nrDNA (ITS; Internal Transcribed Spacer) and cpDNA (psbA-trnH) sequence data analysed with Bayesian Inference and Parsimony. A phylogeny of combined cp- and nrDNA is also presented. These phylogenies are used to assess generic limits and to investigate the biogeographic patterns of Berkheya and its allies. The ITS phylogeny shows five well supported clades of Berkheya, two of which (Clades I and 2) are monophyletic summer rainfall region clades. Clades 3 to 5 are all paraphyletic winter rainfall clades with Cullumia occurring in the third clade, Cuspida occurring in the fourth and Didelta in Clade 5. Both psbA-trnH and combined phylogenies show concordance with the clade distribution shown in the ITS phylogeny. The ITS phylogeny was used to analyse correspondence with Roessler’s (1959) Series. It was found that the phylogeny showed considerable agreement with Roessler’s series, but B. bipinnatifida and B. spinosa of Series Speciosae may require some revision as well as taxa of monotypic series Cruciatae and Angustae. It is suggested that the latter series be merged with Cullumia species to form a single series. Some consideration should be taken to include Didelta species into Series Fruticosae as Didelta occurs in subclade 5b of Clade 5 with other Series Fruticosae taxa. Achene morphology was examined from species from each of the five clades to investigate the relationships of Berkheya and its allies, as well as to determine if there were any consistent achene features for each clade. The structure of surface cells on the fruit, the presence, absence and morphology of twin hairs as well as the structure of the pappus scales were found to be most useful in reflecting phylogenetic relationships within the clades. When compared with the clades of the ITS phylogeny, achene morphology showed consistent characters between taxa occurring in the same clades. As the most comprehensive study involving Berkheya, this phylogenenetic investigation was able to confirm that Berkheya is a paraphyletic genus with Didelta, Cullumia and Cuspida needing to be subsumed into Berkheya. An alternative classification is that taxa of Clade 5 could possibly be erected as an expanded Didelta, separate and sister to Berkheya.

M.Sc. / Pteronia L. is a genus of 70 species of woody shrublets occurring mainly in southern Africa (Leistner, 2000). Published and unpublished ethnobotanical information exists for nine of the species. The uses of these species in traditional medicine are poorly recorded or have remained scientifically unknown. In addition, some unpublished vernacular names have been recorded during this study. Hutchinson and Phillips revised the genus Pteronia in 1917 and grouped the species into four sections. The nine ethnobotanically important species were placed in four sections: Incanae (P. incana and P. cinerea), Papillatae (P. lucilliodes and P. divaricata), Ciliatae (P. camphorata, P. stricta, P. onobromoides and P. adenocarpa) and Glabratae (P. succulenta). Pteronia onobromoides is the original source of Nama buchu that was first recorded by Van der Stel in 1685 (De Wet & Pheiffer, 1979), but which has remained poorly known. Surprisingly, this study has revealed the existence of an important Cape herbal medicine (P. divaricata) for which no record could be found in the scientific literature. Pteronia incana is not widely known for its traditional medicinal uses (although a few have indeed been recorded) but rather as a source of valuable essential oil that has been commercially exploited to some extent. Other species with at least one published anecdote of traditional use include P. adenocarpa, P. camphorata, P cinerea, P. lucilioides, P. stricta and P. succulenta. This means that a total of nine species are now known to have traditional medicinal and/or cosmetic uses. Most of the species are used for intestinal disorders (including stomach pain) and respiratory ailments (coughs, colds and influenza). The topical application of P. onobromoides and P. adenocarpa is clearly aimed at more than just a cosmetic effect and includes the alleviation of pain and the treatment of wounds and skin ailments. These uses all suggest that Pteronia species may have antimicrobial activity and also possible anti-inflammatory and analgesic properties. Pteronia adenocarpa is only known from a single literature record.

No description available.