Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

The mechanisms behind the high level of plant diversity and endemism observed in the Cape Floral Region (CFR) of South Africa have been the focus of many studies. Recently developed methods that employ DNA sequence data are making major contributions in reconstructing evolutionary histories of CFR species. Concurrently, palaeoenvironmental evidence is used increasingly to explain the impact of past climates on species ranges. This paper combines these two approaches by analysing the distribution of genetic diversity of the Afro-montane liverwort Jamesoniella colorata and associating its inferred evolutionary history with major palaeoclimatic trends in South Africa. Liverworts are generally well-suited for phylogeographical studies because they often have low dispersal rates, broad geographical ranges and long evolutionary persistence. In addition, the high among-population diversity observed in J colorata is conducive to the interpretation of significant historical events. The GIS-based bioclimatic envelope shows a strong correlation between potential habitat and the known distribution of J colorata and indicates that sampling in this study was sufficient to make accurate phylogeographical inferences. A combination of phylogeographical data and population genetics evidence suggests that populations of J colorata in the Western Cape Province have experienced range contractions into upper-montane refugia and range expansions into lower altitudes in response to warming and cooling climatic trends, respectively. These range shifts have probably taken place throughout the Quaternary glacial-interglacials cycles, , which are thought to have been influential in shaping modem patterns of diversity. In lV an attempt to assign approximate dates to the two expansion events inferred for J. colorata, an average chloroplast mutation rate was applied to the trnL-F cpDNA mismatch distribution. The results roughly place the expansions within the last glacial period, demonstrating the general accordance of the phylogeographical and palaeoclimatic data. The molecular work in this study also brought into question the taxonomic status of several specimens that showed distinctly divergent DNA sequences. Preliminary morphological inspection of the specimens revealed subtle but clear differences in leaf and stem anatomy that were once associated with J. oenops, a species synonymised with J. colorata in 1971.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-23T19:08:09Z No. of bitstreams: 1 fernandasampaio.pdf: 1013409 bytes, checksum: a971117fc3bdd9c19272fe04cac30974 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-24T12:55:01Z (GMT) No. of bitstreams: 1 fernandasampaio.pdf: 1013409 bytes, checksum: a971117fc3bdd9c19272fe04cac30974 (MD5) / Made available in DSpace on 2017-03-24T12:55:01Z (GMT). No. of bitstreams: 1 fernandasampaio.pdf: 1013409 bytes, checksum: a971117fc3bdd9c19272fe04cac30974 (MD5) Previous issue date: 2009-02-13 / O gênero Lippia é um dos principais da família Verbenaceae e em sua maior parte está concentrado no Brasil, México, Paraguai e Argentina com poucas espécies endêmicas na África. O objetivo deste trabalho foi a construção de uma hipótese filogenética para 39 espécies do gênero Lippia ocorrentes no Brasil, Argentina, Bolívia, Paraguai e Uruguai com base em dados moleculares das regiões ITS, Waxy, TrnL-F e trnQ-rps16. As sequências foram amplificadas e purificadas para posterior seqüenciamento. As análises foram feitas utilizando-se Máxima Verossimilhança e Inferência Bayesiana. O presente trabalho revelou, pela primeira vez, aspectos filogenéticos de espécies do gênero Lippia com base em caracteres moleculares. De modo geral, as árvores filogenéticas baseadas nas diferentes regiões gênicas estudadas revelaram questões importantes como é o caso do monofiletismo da seção Goniostachyum. Outro ponto importante envolve a falta de resolução das seções Dipterocalix, Rhodolippia e Zapania. Dentre elas destaca-se a seção Zapania que constitui em vários aspectos estudados, a seção mais diversa. Embora o presente trabalho tenha mostrado aspectos inéditos com relação à organização filogenética de espécies e seções do gênero Lippia, a questão da especiação no gênero permanece em aberto. É possível que para resolver este problema sejam necessários estudos populacionais e filogeográficos, embasados por uma análise filogenética com maior número de genes e principalmente, envolvendo um maior número de espécies. / Lippia is one of the most important genus of the Verbenaceae family. It is mainly concentrated in Brazil, Mexico, Paraguay and Argentina with few endemic species in Africa. The present study was done in order to construct a phylogenetic hypothesis for 39 species of the genus Lippia from Brazil, Argentina, Bolivia, Paraguay and Uruguay based on molecular data of regions ITS, Waxy, TrnL-F and rps16-trnQ. The sequences were amplified and purified for subsequent sequencing. The phylogenetic analyses were done using the Maximum Likelihood and Bayesian Inference. It was possible to show for the first time, phylogenetic aspects of the genus Lippia based on molecular data. In general, the phylogenetic trees based on different gene regions revealed important points such as the monophyly of Goniostachyum section. Another important point involves the lack of resolution of the sections Dipterocalix, Rhodolippia and mainly Zapania which is the most diverse among them. Although this work has shown new aspects about the phylogenetic organization of sections and species of the genus Lippia, the speciation process of the genus remains an open question. To resolve this problem, additional studies using phylogeographic and population genetics approaches, based on a phylogenetic analysis with greater numbers of genes and mainly involving a great number of species should be necessary.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

The “Lomandra complex” (or Lomandra grouping) is an informally recognised grade resulting from the subdivision of the Laxmanniaceae into two groups (Conran, 1998); the ‘Lomandra complex” (Acanthocarpus, Chamaexeros, Lomandra, Romnalda and Xerolirion), and the remainder as the Arthropodoids (Arthropodium, Chamaescilla, Cordyline, Eustrephus, Laxmannia, Murchisonia, Sowerbaea, Thysanotus and Trichopetalum). Laxmanniaceae are an Australiacentred, tropical to temperate family of 14 genera with around 180 species from Australasia, SE Asia, the Mascarenes, New Caledonia, New Guinea, New Zealand, North and South America and the Pacific Islands. There have been no detailed phylogenetic studies in Laxmanniaceae and the relationships within and between the genera is poorly understood. This study utilised molecular data from chloroplast trnL-F and nuclear ribosomal ITS2 regions analysed with maximum parsimony and bayesian inference methods to reconstruct the phylogeny of the genera of the ‘Lomandra complex’, using species of Arthropodium, Eustrephus, Laxmannia and Thysanotus as outgroups. The molecular phylogeny shows that Lomandra forms four primary clades; with members from the classical anatomy, inflorescence-defined section and series distributed amongst these, typically in large islands. The monotypic genus Xerolirion resides deeply within Lomandra, raising questions about the appropriateness of this genus. Additionally, the other genera of the Lomandra complex (Acanthocarpus, Chamaexeros and Romnalda) form a clade positioned sister to one of four primary Lomandra clades, but nested inside Lomandra sens. lat., indicating a closer relationship between these genera than previously thought. The affiliation of these bisexual, hermaphroditic genera within the otherwise unisexual, dioecious Lomandra clade supports the recognition of the ‘Lomandra complex’ as an expanded genus, Lomandra; and represents either an example of the evolution of unisexuality followed by reversion, or else multiple losses of hermaphrodite flowers. Morphological and anatomical data were obtained for leaf and floral macroscopic characters, mid-leaf section anatomy and cuticle microscopic features and analysed with maximum parsimony and bayesian inference methods to reconstruct the anatomical phylogeny. These data were also utilised to generate a DELTA key for identifying species of Lomandra from a combination of macroscopic morphological and microscopic leaf anatomical features. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1385938 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2010

Variability in the genetic information DNA tracking individuals carry is easy to detect using molecular markers. In the thesis we examined related Dracaena species. For the study of genetic diversity in the genus Dracaena are used mainly noncoding regions of cpDNA, spacer trnH -- psbA, regions trnL -- trnF and trnS -- trnG -- trnG, which are more variable than coding regions. Also used in this work were coding regions of matK and rbcL. In the genus Dracaena belongs xerophytic species that are characterized by typical shaped treetop. 14 representatives of species were used in thesis growing in tropical regions of the African continent and adjacent islands and the southeastern part of the Arabian peninsula. They are monocotyledonous trees with atypical abilities of secondary thickness of trunk, which I find interesting. The massive trunk is very strong and there is potencial to used it for wood. Trees are very significant for their red plant sap which flowing from demaged trunk. The sap is very precious resource which is used in many areas of industry, for example pharmacy, traditional medicine, dye making etc. Determination of genetic affinity was based on an amplification of cpDNA template of individual Dracaena samples with primers for the studied regions. Data was obtained and evaluated by Multiple alignment program ClustalX and BioEdit after their sequencing. Evalueted data was used to create dendograms affinity. According the resulting phylogenetic tree we find out similarities and identified relationship of the monitored species of the genus Dracaena. The main purpose of research was to get answers to understand phylogenetic relationship between group of Dracaena forestry used trees. The thesis was made in cooperation of Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology of Mendel University in Brno.

Molecular and morphologic studies were used to determine the evolution, classification and differentiation of Nymphaea odorata. Molecular analyses of the nuclear internal transcribed spacer (ITS) region, the chloroplast trnL-F region, and inter-simple sequence repeat (ISSR) markers determined the variation present between and within two species of Nymphaea. The ITS region resulted in a phylogeny depicting strong separation between species (N. mexicana and N. odorata) and some separation between N. odorata's subspecies. The ITS region contained polymorphisms, which upon SAHN clustering and principle coordinate (PCOA) and minimum spanning tree (MST) analyses produced groups similar to the clades in the ITS phylogeny. Sixteen accessions were chosen for trnL-F analysis, where a subspecies-specific molecular marker was found. In most accessions the marker confirmed the original subspecies classification. Molecular analyses using ISSRs characterized among population variation in N. odorata and N. mexicana using five primers. ISSR markers among populations were highly variable within a species and were used in UPGMA, PCOA and MST analysis, which resulted in separation between the subspecies. Both univariate and multivariate analyses were performed on quantitative and qualitative morphological characters. An analysis of variance resulted in six morphological characteristics that were statistically significant (P< 0.05), the majority being leaf blade characteristics. Multivariate statistics of principle component analysis and discriminate analysis resulted in groups for each subspecies, both emphasized the importance of quantitative leaf blade characteristics. Overall, both morphology and molecular characteristics supported the classification of subspecies for ssp. odorata and ssp. tuberosa, due a lack of strong segregation of characteristics. / Master of Science

The Malacothamnus alliance consists of three genera, Iliamna, Malacothamnus, and Phymosia. The genera are considered taxonomically complex since hybridization freely occurs, polyploidy levels vary, and there is a lack of distinct morphological characters to delineate taxa. Several taxonomic treatments have been prepared for each genus, but relationships within the genera and the relationship of the Malacothamnus alliance to others in the Malvaceae remains unknown. This multifaceted study aimed to (a) examine the monophyly of the Malacothamnus alliance and its position in the Malvaceae, (b) determine the relationships between genera in the alliance, (c) compare variation of nuclear and chloroplast genes in the alliance, (d) prepare revised taxonomic treatments for Iliamna and Malacothamnus, and (e) examine the probability of successful hybridization in Iliamna. The monophyly of the Malacothamnus alliance was not confirmed using DNA sequences of both nuclear and chloroplast regions. In Iliamna, little sequence variation was detected among taxa in the Rocky Mountains; however, the nuclear and chloroplast regions conflicted with regard to the relationships of the western and eastern taxa. An ancestral copy of the chloroplast genome is shared between the two eastern U.S. Iliamna species and Phymosia (Bahamas and Mexico). The nuclear ITS sequences indicated the western U.S. Iliamna species were more closely related to Phymosia and Malacothamnus than to other species in Iliamna. Neither data set provided sufficient variation to resolve relationships of species in Malacothamnus. Genetic variation and the feasibility of hybridization in Iliamna supported the results of the broader phylogenetic studies. Iliamna corei and I. remota are recently derived from I. rivularis. Hybrid offspring of I. corei and I. remota had higher viability and fecundity than did hybrids between crosses of either species and I. rivularis. The Virginia populations of I. corei and I. remota are more genetically similar than either is to Illinois populations of I. remota. However, the species are morphologically distinct and can easily be distinguished from others in the genus. Revised taxonomic treatments for Iliamna and Malacothamnus based on surveys of herbarium material are presented. Taxonomic revisions include the new combinations of Iliamna grandiflora subsp. grandiflora and I. grandiflora supsp. crandallii and the resurrection of Malacothamnus hallii and M. orbiculatus. / Ph. D.