Thesis (MSc (Botany and Zoology))--Stellenbosch University, 2008. / Sequence data from the Internal Transcribed Spacer (ITS) of the nuclear ribosomal DNA were used to study the phylogenetic relationships in the genus Ursinia Gaertn. (Asteraceae, Anthemideae) in the southern African region. Closely related genera, i.e. Cotula L., Osteospermum L. and Agoseris Raf., were used as outgroups. The study also included maximum parsimony and principal component analyses. The taxa within the genus Ursinia had previously been classified into two subgenera, Ursinia and Sphenogyne R.Br., mainly on the basis of distinct cypsela characters. The maximum parsimony, principal component and the phylogenetic analyses revealed two subgenera, corresponding to the existing subgeneric classification. Principal component analysis shows that the pappus, the number of pappus bristles and the colour of the cypsela are the most informative characters. However, the low number of phylogenetically informative characters of the ITS sequences, the poor resolution in the consensus tree, and low branch support values indicate that the ITS data contain weak phylogenetic signals. The low bootstrap values for many nodes suggest that one should be cautious in using the ITS region alone to make final conclusions about the origin and evolution of taxa. In maximum parsimony analysis, the RI, CI and bootstrap values are low; principal component analysis values are also low. Furthermore, there is a lack of resolution in subgenus Sphenogyne. In the literature, Ursinia is divided into seven series but they were not retrieved as monophyletic in this study, probably because of short branch lengths in the phylogeny. Further molecular data are therefore required to be able to support or reject the present classification. Maximum parsimony, principal component and molecular analyses show that U. trifida f. calva Prassler and U. trifida (Thunb.) N.E.Br. f. trifida are not sister taxa, supporting the recognition of these two taxa as separate species. The Ursinia taxa from the summer-rainfall region are not monophyletic and are sister to a clade of Cape species. This supports a hypothesis that Ursinia migrated from the Cape into the Drakensberg which has been shown for a number of other Cape groups that have Drakensberg relatives.

Lychnophora ericoides is a shrub like species, endemic to rock outcrops areas, whose cultivation practices are unknown and its irregular maturation being the great problem for seedling production. The objective of the work was to evaluate the germination of L. ericoides cypsela collected from across different altitudes of a population occurring in the Serra da Bocaina, region of Alto Paranaíba, Minas Gerais, and submitted to methods for cypselas selection with relation to density. In the first experiment, arnica capitulum of 20 access (altitudes between 1102 and 1245m) formed a completely randomized design, with 20 access (treatments) and four repetitions, in groups with 50 cypselas removed from the borders of the capitulum. In the second experiment, samples of the same cypselas were placed in a blower for 3 minutes and 20 seconds, the heaviest being separated in two groups. Half of the cypselas were washed in running water for 24 hours and the other half were submerged in sulfuric acid for 1 minute and soon after washed in running water for 24 hours. After the separation, the germination test was set up in a completely randomized design in factorial scheme of 2 x 20, the first factor corresponding to treatments (water and sulfuric acid) and the second factor, to the 20 access in four repetitions containing 50 cypselas. In both experiments, the cypsela were distributed in gerbox containing blotting paper humidified with distilled water, being counted, first the cypselas germinated in function of the protrusion of the radicle and, in the second, normal seedlings. In the first experiment, the cypselas presented low percentage of germination (maximum 15%). The small difference between the germination percentage and viability indicated that few cypselas at the end of the germination test were viable, a result proven by the high percentage of empty cypselas (above 65.5%). The percentage relative to germination (full cypselas) showed high capacity of cypsela germination (72.38, 78.13 and 66.85% for cypselas from access 1, 3 and 5, respectively). The variation of the altitude gradient of 143 m was not lineally related to the presence of empty seeds, not even to the physiologic quality of the cypselas. The cypsela germination was slow and distributed over time. After the density test, the maximum germination was also low (maximum 34% for the access 2 submitted to sulfuric acid). The use of sulfuric acid after the density test, in a general way, improved the quality of the cypselas and increased the percentage of cypsela germination of same. / Lychnophora ericoides, conhecida como arnica-do-campo, é uma espécie arbustiva, endêmica dos campos rupestres, cujas práticas de cultivo são desconhecidas, sendo a maturação desuniforme o grande problema para produção de mudas. O objetivo do trabalho foi avaliar a germinação de cipselas de L. ericoides coletados de acessos em diferentes altitudes de uma população ocorrente na Serra da Bocaina, região do Alto Paranaíba, Minas Gerais e submetidos a métodos para seleção dos cipselas quanto à densidade. No primeiro experimento, capítulos florais de 20 acessos (altitudes entre 1102 e 1245 m) formaram um delineamento inteiramente casualizado, com 20 acessos (tratamentos) e quatro repetições, em parcelas com 50 cipselas retirados das bordas dos capítulos. No segundo experimento, amostras dos mesmos cipselas foram colocadas em soprador por 3 minutos e 20 segundos, sendo os mais pesados separados em dois grupos. Metade dos cipselas foi lavada em água corrente por 24 horas e a outra metade ficou submersa em ácido sulfúrico por 1 minuto e em seguida lavados em água corrente por 24 horas. Após a separação, o teste de germinação foi instalado em delineamento inteiramente casualizado em esquema fatorial 2 x 20, sendo o primeiro fator correspondente aos tratamentos (ácido sulfúrico e água) e o segundo fator, aos acessos em quatro repetições contendo 50 cipselas. Em ambos os experimentos, os cipselas foram distribuídos em gerbox contendo papel mata-borrão umedecido com água deionizada, sendo contados, no primeiro, os cipselas germinados em função da protrusão da radícula e, no segundo, plantas normais. No primeiro experimento, os cipselas apresentaram baixo percentual de germinação (máximo 15%). A pequena diferença entre o percentual de germinação e de viabilidade indicou que poucos cipselas no final do teste de germinação estavam viáveis, resultado comprovado pelo elevado percentual de cipselas chochos (acima de 65,5%). O percentual relativo de germinação (cipselas cheios) mostrou alta capacidade de germinação dos cipselas (78,13; 72,38 e 66,85% para cipselas dos acessos 7, 11 e 20, respectivamente). A variação do gradiente de altitude de 143 m não esteve linearmente relacionada à presença de cipselas chochos, nem mesmo com a qualidade fisiológica dos mesmos. A germinação dos cipselas foi lenta e distribuída no tempo. Após o teste densimétrico, a germinação máxima também foi baixa (máximo 34% para cipselas do acesso 2, quando submetidos ao ácido sulfúrico). A utilização de ácido sulfúrico após o teste densimétrico, de maneira geral, aumentou o percentual de germinação dos cipselas de alguns acessos. / Mestre em Agronomia