<p>The <italic>Polypodium vulgare<italic> complex (Polypodiaceae) comprises a well-studied group of fern taxa whose members are cryptically differentiated morphologically and have generated a confusing and highly reticulate species cluster. Once considered a single species spanning much of northern Eurasia and North America, <italic>P. vulgare<italic> has been segregated into approximately 17 diploid and polyploid taxa as a result of cytotaxonomic work, hybridization experiments, and isozyme studies conducted during the 20th century. Despite considerable effort, however, the evolutionary relationships among the diploid members of the <italic>P. vulgare<italic> complex remain poorly resolved, and several taxa, particularly allopolyploids and their diploid progenitors, remain challenging to delineate morphologically due to a dearth of stable diagnostic characters. Furthermore, compared to many well-studied angiosperm reticulate complexes, relatively little is known about the number of independently-derived lineages, distribution, and evolutionary significance of the allopolyploid species that have formed recurrently. This dissertation is an attempt to advance systematic knowledge of the <italic>Polypodium vulgare<italic> complex and establish it as a "model" system for investigating the evolutionary consequences of allopolyploidy in ferns. </p><p>Chapter I presents a diploids-only phylogeny of the <italic>P. vulgare<italic> complex and related species to test previous hypotheses concerning relationships within <italic>Polypodium<italic> sensu stricto. Analyses of sequence data from four plastid loci (<italic>atpA<italic>, <italic>rbcL<italic>, <italic>matK<italic>, and <italic>trnG-trnR<italic>) recovered a monophyletic <italic>P. vulgare<italic> complex comprising four well-supported clades. The <italic>P. vulgare<italic> complex is resolved as sister to the Neotropical <italic>P. plesiosorum<italic> group and these, in turn, are sister to the Asian endemic <italic>Pleurosoriopsis makinoi<italic>. Divergence time analyses incorporating previously derived age constraints and fossil data provide support for an early Miocene origin for the <italic>P. vulgare<italic> complex and a late Miocene-Pliocene origin for the four major diploid lineages of the complex, with the majority of extant diploid species diversifying from the late Miocene through the Pleistocene. Finally, node age estimates are used to reassess previous hypotheses, and to propose new hypotheses, about the historical events that shaped the diversity and current geographic distribution of the diploid species of the <italic>P. vulgare<italic> complex. </p><p>Chapter II addresses reported discrepancies regarding the occurrence of <italic>Polypodium calirhiza<italic> in Mexico. The original paper describing this taxon cited collections from Mexico, but the species was omitted from the recent <italic>Pteridophytes of Mexico<italic>. Originally treated as a tetraploid cytotype of <italic>P. californicum<italic>, <italic>P. calirhiza<italic> now is hypothesized to have arisen through hybridization between <italic>P. glycyrrhiza<italic> and <italic>P. californicum<italic>. The allotetraploid can be difficult to distinguish from either of its putative parents, but especially so from <italic>P. californicum<italic>. These analyses show that a combination of spore length and abaxial rachis scale morphology consistently distinguishes <italic>P. calirhiza<italic> from <italic>P. californicum<italic> and confirm that both species occur in Mexico. Although occasionally found growing together in the United States, the two species are strongly allopatric in Mexico, where <italic>P. californicum<italic> is restricted to coastal regions of the Baja California peninsula and neighboring Pacific islands and <italic>P. calirhiza<italic> grows at high elevations in central and southern Mexico. The occurrence of <italic>P. calirhiza<italic> in Oaxaca, Mexico, marks the southernmost extent of the P. vulgare complex in the Western Hemisphere.</p><p>Chapter III examines a case of reciprocal allopolyploid origins in the fern <italic>Polypodium hesperium<italic> and presents it as a natural model system for investigating the evolutionary potential of duplicated genomes. In allopolyploids, reciprocal crosses between the same progenitor species can yield lineages with different uniparentally inherited plastid genomes. While likely common, there are few well-documented examples of such reciprocal origins. Using a combination of uniparentally inherited plastid and biparentally inherited nuclear sequence data, we investigated the distributions and relative ages of reciprocally formed lineages in <italic>Polypodium hesperium<italic>, an allotetraploid fern that is broadly distributed in western North America. The reciprocally-derived plastid haplotypes of <italic>Polypodium hesperium<italic> are allopatric, with populations north and south of 42&#730; N latitude having different plastid genomes. Biogeographic information and previously estimated ages for the diversification of its diploid progenitors, lends support for middle to late Pleistocene origins of <italic>P. hesperium<italic>. Several features of <italic>Polypodium hesperium<italic> make it a particularly promising system for investigating the evolutionary consequences of allopolyploidy. These include reciprocally derived lineages with disjunct geographic distributions, recent time of origin, and extant diploid progenitor lineages. </p><p>This dissertation concludes by demonstrating the utility of the allotetraploid <italic>Polypodium hesperium<italic> for understanding how ferns utilize the genetic diversity imparted by allopolyploidy and recurrent origins. Chapter IV details the use of high-throughput sequencing technologies to generate a reference transcriptome for <italic>Polypodium<italic>, a genus without preexisting genomic resources, and compare patterns of total and homoeolog-specific gene expression in leaf tissue of reciprocally formed lineages of <italic>P. hesperium<italic>. Genome-wide expression patterns of total gene expression and homoeolog expression ratios are strikingly similar between the lineages--total gene expression levels mirror those of the diploid progenitor P. amorphum and homoeologs derived from <italic>P. amorphum<italic> are preferentially expressed. The unprecedented levels of unbalanced expression level dominance and unbalanced homoeolog expression bias found in <italic>P. hesperium<italic> supports the hypothesis that these phenomena are pervasive consequences of allopolyploidy in plants.</p> / Dissertation

A large sector of the forestry industry of South Africa comprises Eucalyptus species, covering approximately 49% of the forestry plantation area. Polyploidy induction has become an attractive tool to increase yield and reduce invasiveness in forestry species. Polyploidy induction in Eucalyptus using colchicine treatments on seed and axillary buds was undertaken to produce tetraploids that could be used in breeding programmes; specifically to increase yield and decrease species invasiveness through the production of triploids after crossing with diploid parents. Eight seedlots of E. urophylla and seven of E. grandis were treated with four colchicine concentrations (0.00, 0.01, 0.03, 0.05%) at two exposure times (18 h and 24 h), treating two seeds per treatment, repeated eight times. For axillary bud induction, 20 buds of two E. grandis clones and three E. grandis × E. urophylla hybrids and one E. grandis × E. nitens hybrid were treated with four colchicine concentrations (0.0, 0.5, 1.0, 1.5%) for three consecutive days. A known tetraploid hybrid E. grandis E. camaldulensis and its corresponding diploid were included as reference material. Seedlings and bud sports were pre-screened by determining stomatal guard cell lengths. Seedlings and bud sports displaying cell lengths significantly (p<0.0001) larger than the diploid were selected as putative polyploids. Polyploidy was then confirmed by quantifying the DNA content using flow cytometry. Stomatal frequencies and guard cell chloroplast frequencies were also determined in the induced tetraploid seedlings to evaluate their suitability to discern between ploids. All putative polyploidy seedlings, identified in the pre-screening process, were confirmed, using flow cytometry, as either tetraploids or mixoploids. Of the 17 E. urophylla putative polyploids, from various seedlots, six were tetraploid and 11 mixoploid. In E. grandis one of the five putative polyploids, from various seedlots, was tetraploid and four mixoploid. Pre-screening of bud sports was less accurate; only four of the 12 E. grandis hybrid putative polyploids were mixoploid and only three of the six E. grandis putative polyploids were mixoploid. E. urophylla seedlings were more sensitive to colchicine than E. grandis seedlings displaying a lower survival rate (52%) than E. grandis (63%). Extreme treatments that caused the lowest survival rates were also responsible for most of the polyploidy successful inductions; 0.05%/18 h and 0.05%/24 h for E. urophylla and 0.03%/24 h and 0.05%/24 h for E. grandis. Phenotypic effects of colchicine included shorter, thicker roots and hypocotyls; darker leaves; longer and narrower leaves in some tetraploids; and asymmetrical leaf margins in many mixoploids and tetraploids compared with the controls. In the tetraploids, stomata were significantly larger (p<0.0001) and less frequent (p<0.001). A significant (p<0.001) increase in the number stomatal chloroplasts was also ascertained. Confirmed mixoploid seedlings all displayed tetraploid leaves based on stomatal size and thus classified as periclinal chimeras. In bud sports, only leaves with islands of diploid and tetraploid stomata in the confirmed mixoploids were encountered. Mixoploid bud sports were thus either sectional or mericlinal chimeras. Stomatal size proved to be a suitable pre-screening method, especially in polyploidy induction in seedlings. Additionally confirmed tetraploids exhibited significantly different stomatal frequencies and stomatal chloroplast frequencies compared with the diploids, thus proving to be suitable detection methods for polyploidy screenings. Polyploidy induction in seed was effective, however, less effective in axillary buds which requires further research to refine methods. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Nicotine, nornicotine, anabasine and anatabine are four major alkaloids in tobacco, of which nicotine is predominant. In many tobacco cultivars and also in other Nicotiana species, nicotine is converted to nornicotine, which in turn gives rise to potent carcinogen NNN. Nicotine to nornicotine conversion via nicotine-N-demethylation is mediated by the CYP82E family of P450 enzymes. Tobacco (Nicotiana tabacum) converts in senescing leaves, while its diploid progenitors N.tomentosiformis and N.sylvestris convert in both green and senescing and only in senescing leaves, respectively. Previously it has been shown that N.tomentosiformis has different active conversion loci in green and senescing leaves. The green leaf conversion enzyme CYP82E3 is inactivated in tobacco by a single amino acid substitution, while the senescing leaf converter enzyme CYP82E4 is active in tobacco, which gave tobacco a ‘senescing leaf converter’ phenotype. In nonconverter tobacco, CYP82E4 shows transcriptional silencing. The nicotine-N-demethylase gene NsylCYP82E2 involved in nicotine to nornicotine conversion in senesced leaves of N. sylvestris was isolated. NsylCYP82E2 is active in N. sylvestris, but it has become inactivated in tobacco through mutations causing two amino acid substitutions. The conversion factor from N.sylvestris was characterized and a model for the alkaloid profile evolution in the amphidiploid N.tabacum from its diploid progenitors was proposed. Regulation of conversion phenomenon was tested under different spatio-temporal conditions and various stresses. The promoter region for NtabCYP82E4 was isolated and promoter-reporter construct was used to determine that NtabCYP82E4 is specifically induced only during senescence. This pattern correlates with the nornicotine accumulation as measured by alkaloid profiling. Thus the regulatory regions of NtabCYP82E4 represent a senescence specific promoter. In another project functional characterization of tobacco EIN2 (NtabEIN2) was undertaken. EIN2 from tobacco and N.sylvestris were cloned, their genomic structure was deduced and NtabEIN2 was silenced using RNAi approach. Silenced plants showed significant delay in petal senescence and abscission; as well as anther dehiscence, pod maturation, pod size, seed yield and defense against tobacco hornworm. Mechanism of delayed petal senescence phenotype, including possible cross-talk with Auxin Response Factor 2 and potential involvement of tasiRNA3 were also investigated.

Ferns are one of the three main clades of vascular plants. They have few easily studied morphological characters, reflected in a historically unstable classification. The fern genus Woodsia is known to have a complex evolutionary history including numerous polyploid taxa and hybrids. It is a cosmopolitan group of small rock loving ferns mainly found in montane areas. This thesis aims at analyzing the patterns of diploid and polyploid evolution in Woodsia and to resolve and classify the relationships of Woodsiaceae and the other families in the large fern clade Eupolypods II. The Eupolypods II family relationships were inferred with DNA sequences from 81 specimens representing all major lineages. This resulted in the first well supported phylogeny of this clade and revealed Woodsiaceae to be non-monophyletic. The genera previously placed in this family were reclassified into five new or resurrected families. Swedish fern genera that have changed family classification are Woodsia (hällebräknar), now in the monogeneric family Woodsiaceae, Athyrium (majbräknar), now  in Athyriaceeae and Cystopteris (stenbräknar) and Gymnocarpium (ekbräknar) now in Cystopteridaceae. To analyze the evolution of Woodsia, phylogenies were produced from five plastid and two nuclear regions sequenced from 188 specimens. The results show that most taxa in Woodsia are polyploid. Polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young and many of the polyploid taxa seem to have formed multiple times. The results also address several taxonomic and biogeographic questions. In the process of the work we made methodological advancements and developed 20 new low copy nuclear marker regions as well as a software pipeline for finding primers in transcriptome datasets. The alignment editor software AliView was developed for handling the increasing size datasets in a user friendly way. In conclusion this thesis provides new insights into the complexities of the evolution of a fern genus in which much of the diversity is accommodated in young species formed through polyploidization. It provides a framework of phylogenetic relationships at different levels that both answers long standing questions and generates new ones.

Lic.-avh. Härnösand Uppsala : Mitthögskolan : Sveriges lantbruksuniv. : 2001. / Härtill 2 uppsatser.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

La protéine HBx du virus de l'hépatite B (VHB) potentialise la survenue du carcinome hépatocellulaire (CHC). Cependant, les mécanismes par lesquels, HBx favorise l'instabilité génétique lors de la prolifération hépatique restent flous. La polyploïdisation hépatocytaire participe à la diversité génétique dans le foie. La modulation de la polyploïdie par l'HBx contribuerait-elle au développement de la maladie hépatique ? Ainsi, la polyploïdisation au cours du développement et de la maladie hépatique induite par le tétrachlorure de carbone ou le diéthylnitrosamine, a été évaluée dans les souris transgéniques FL-HBx (forme complète). Au cours du développement postnatal et dans la maladie hépatique, FL-HBx inhibe la binucléation hépatique au profit de noyaux polyploïdes (? 4n) par la dérégulation des transitions G1/S et G2/M, et l'accumulation d'ADN altérés. Une polyploïdisation similaire a été observé dans des souris avec un foie humanisé et infecté par le VHB. Dans les souris FL-HBx, l'initiation du CHC est associée à l'inactivation de ChK1, l'inhibition de Mre11, Rad51 et de l'apoptose, et à la surexpression d'IL-6 tandis que dans la fibrose, l'augmentation d'?-sma, PdgfR-?, TGF-?, TNF-? et la perte de l'expression de la glutamine synthétase ont été observées. De plus, les hépatocytes FL-HBx traitées présentent une prolifération anormale avec une forte expression de Ly6D, GpC3 et AFP. En conclusion, nos résultats montrent que par la surexpression de PLK1 via p38/ERK, FL-HBx induit une polyploïdisation pathologique du foie conduisant à la propagation d'ADN altérés et à l'apparition de marqueurs tumoraux au cours de la fibrose hépatique et de l'initiation du CHC. / Hepatitis B virus X protein (HBx) is involved in the development of hepatocellular carcinoma (HCC). However, how HBx promotes genetic instability or DNA damage during liver proliferation remains unclear. For that, we used mice transgenic for the full-length HBx (FL-HBx) to investigated the impact of HBx expression on polyploidization during normal liver proliferation and in liver diseases (fibrosis : carbon tetrachloride and HCC : diethyl nitrosamine, treatments). During postnatal liver development as well as in liver diseases, FL-HBx inhibits liver binucleation and triggers early production of polyploid nuclei (≥ 4n). These features were associated with aberrant G1/S and G2/M transitions and the propagation of DNA damage. Furthermore, hepatitis B virus infection, in liver humanized mouse model, shows similar deregulation of hepatocytes polyploidization. In FL-HBx animals, HCC initiation was associated with impairment of ChK1 activation and Mre11 and Rad51 expression (DNA repair proteins), inhibited apoptosis and upregulated IL-6 transcription while in fibrosis, increased expression of α-sma, PdgfR-β, TGF-β, TNF-α as well as a defect in glutamine synthetase expression were observed. In addition, treated FL-HBx animals displayed marked alterations to the cell cycle associated with stronger expression of HCC progenitor cell markers (Ly6D, GpC3, AFP). Finally, we showed that FL-HBx protein induces pathological polyploidization of hepatocytes by upregulating PLK1 through p38/ERK Mapks pathways. That promotes a loss of genomic integrity and an increase of hepatocytes expressing tumor progenitor cell markers during liver fibrosis and HCC initiation.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-03-17T14:46:25Z No. of bitstreams: 1 arquivototal.pdf: 1177130 bytes, checksum: e74f45fd76a0d2bbc5259a38fb6825cb (MD5) / Made available in DSpace on 2016-03-17T14:46:25Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1177130 bytes, checksum: e74f45fd76a0d2bbc5259a38fb6825cb (MD5) Previous issue date: 2010-03-10 / The castor bean plant (Ricinus communis L.) is a diploid specie that have chromosomes in number of 2n=2x=20. The castor bean plantlets are hard to be in vitro regenerated because its recalcitrance requires a good in vitro regeneration protocol. The aim of this work was to develop an in vitro and ex vitro polyploidy induction protocol for castor bean (Ricinus communis). Experiments were conducted in Tissue Culture Laboratory of Agricultural Sciences Center from Universidade Federal da Paraíba, Campus II, Areia – PB. Castor bean seeds of variety E1P17 A/B were utilized. In the 1 experiment, the explants had been inoculated along eight different nutritive mediums of Margara (N5Ca, N30Ca, N30K, N15K, N15Ca, N45K, N5K, N30NH4), in the 2 experiment, in médium N5Ca with 6 sucrose concentrations (0, 1,0, 2,0, 3,0, 4,0 e 5,0%,), in the 3 experiment, the plantlets had being added in Trifluralin solutions with 0, 5, 10, 15, 20, 25 μM concentrations for 16 hours, and in the 4 experiment was applied a Trifluralin solution (10 M), which treatments were T0 (no application), T1 (only one application), T2 (two applications) e T3 (three applications) over the apical meristem of the plantlets. Therefore, based on these experiments results, the conclusion is that it is possible to propagate in vitro castor bean plant utilizing N5Ca medium of Margara and sucrose by 3% had shown the best morphogenetic result. For in vitro induction of the castor bean polyploidy, might be tested less than 10 M concentrations or reduce exposition time for 16 hours; and morphological variations are important at polyploidy plants identification in castor bean plants. / A mamoneira (Ricinus communis L.) é uma espécie diplóide com número de cromossomos 2n=2x=20. Suas plântulas são difíceis de serem regeneradas in vitro devido a sua recalcitrância necessita de um bom protocolo de regeneração. O presente trabalho teve o objetivo de desenvolver um protocolo para induzir a poliploidia in vitro e ex vitro na mamona (Ricinus communis). Os experimentos foram conduzidos no Laboratório de Cultura de Tecidos do Centro de Ciências Agrárias na Universidade Federal da Paraíba Campus II na cidade de Areia – PB. Foram utilizadas sementes de mamoneira da variedade E1P17 A/B. No experimento 1, os explantes foram inoculados em oito diferentes de meios nutritivos de Margara(N5Ca, N30Ca, N30K, N15K, N15Ca, N45K, N5K, N30NH4), no experimento 2, em meio N5Ca com 6 concentrações de sacarose(0, 1,0, 2,0, 3,0, 4,0 e 5,0%,), no 3° experimento as plântulas foram colocadas em soluções de Trifluralina nas concentrações de 0, 5, 10, 15, 20, 25 μM por 16h, e no experimento 4 foi aplicado a solução de Trifluralina (10 M) cujos tratamentos foram T0 (sem aplicação), T1 (única aplicação), T2 (duas aplicações) e T3 (três aplicações)sobre o meristema apical das plântulas. Diante dos resultados apresentados nos experimentos pode concluir que é possível propagar mamoneira in vitro utilizando o meio N5Ca de Margara, e sacarose a 3% apresentou melhor resposta morfogênica. Para a indução in vitro de poliplóides de mamoneira deve-se testar concentrações inferiores a 10 M ou diminuir o tempo de exposição de 16 horas; e as variações morfológicas são importantes na identificação de plantas poliplóides em mamoneira.

This thesis is aimed to compare 4n sterlet (Acipenser ruthenus) and 8n and 12n siberian sturgeon (Acipenser baerii) sperm. Relative quantitative values and % of live spermatozoa as a qualitative factor have been compared between species. At the same time influences of four different types of substances (CPE, Ovopel, GnRHa25 and GnRHa75) on sperm quality were compared.

Orientador: Marlies Sazima / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-16T08:56:09Z (GMT). No. of bitstreams: 1 Brito_ViniciusLourencoGarcia_M.pdf: 8743517 bytes, checksum: efdc732f7b02ccea2c628acf24677361 (MD5) Previous issue date: 2010 / Resumo: As montanhas apresentam alta diversidade e diferentes condições ambientais ao longo de curtas distâncias. Assim, as montanhas são ideais para estudos ecológicos e evolutivos que podem somar valores e aprimorar projetos de conservação. Em altitudes elevadas as condições ambientais podem reduzir a quantidade de polinizadores, principalmente de abelhas. Desta forma, em espécies estritamente melitófilas, características como a fenologia, o sistema reprodutivo, o fluxo de pólen e a estrutura genética das populações pode variar ao longo do gradiente, uma vez que a transferência de grãos de pólen aos estigmas co-específicos também varia ao longo do gradiente. No caso de áreas de elevada altitude, a transferência de pólen é limitada (limitação de pólen), reduzindo as possibilidades de polinização cruzada. O presente estudo tem por objetivo obter informações sobre a biologia da polinização, reprodução e genética de duas populações de Tibouchina pulchra (Melastomataceae) ocorrentes em duas áreas de gradiente altitudinal: Núcleo Santa Virgínia (NSV) e Núcleo de Desenvolvimento Picinguaba (NDP) do Parque Estadual da Serra do Mar. Foram feitas observações mensais para definir padrões e estratégias de floração, registrar dados sobre a biologia floral e reprodutiva, além de verificar a riqueza e abundância dos polinizadores e caracterizar as interações dessa espécie com as abelhas visitantes. Material genético de 44 indivíduos do NSV e 45 indivíduos do NDP foram coletados para o desenvolvimento e caracterização de 12 loco microssatélites polimórficos e estes foram utilizados para fazer análises de agrupamento, ordenação bayesiana e medidas de diversidade genética nas duas populações. Os aspectos da biologia reprodutiva são diferentes entre as duas áreas: na área elevada a florada é mais intensa, a produção de pólen é menor, há limitação na transferência de pólen, mas a fertilização de sementes provindas de polinização cruzada manual é maior. Na outra área são produzidos mais frutos e há maior riqueza e abundância de polinizadores. Ocorre diferenciação genética entre as populações, mas com uma interface de contato entre elas, além de menor diversidade genética na população da área elevada. Estes resultados indicam que a ausência de polinizadores na região de altitude elevada está associada a diferentes estratégias na biologia floral e reprodutiva para balancear a limitação de pólen. Além disso, diferentes dinâmicas de fluxo gênico mediado pelo pólen nas duas populações e as características de distribuição e reprodução podem influenciar a estrutura e a diversidade genética de Tibouchina pulchra ao longo da Serra do Mar / Abstract: Mountains have high diversity and many environmental conditions at short distances. Hence, they are an ideal place to develop ecological and evolutionary studies that can improve conservation projects. At high altitudes, the environmental conditions reduce pollinator abundance, mainly bees. Therefore, traits such as phenology, breeding system and genetic structure of plant populations pollinated by bees could vary in an altitudinal gradient, because pollen grain transference to co-specific flowers varies also. At high altitudes pollen transference is limited (pollen limitation) reducing cross-pollination. The main goal of the present study was to obtain information about pollination biology, breeding system and genetic structure of two populations of Tibouchina pulchra (Melastomataceae) that occur in two different areas of an altitudinal gradient: Núcleo Santa Virgínia (NSV) and Núcleo de Desenvolvimento Picinguaba (NDP) of Parque Estadual da Serra do Mar. Field work was done monthly to describe the flowering patterns and strategies, record floral and reproductive biology, verify pollinator diversity and characterize the interactions among this plant species and bee visitors. Genetic material was collected from 44 Tibouchina pulchra individuals of NSV and 45 individuals of NDP to developed and characterize 12 microsatellite polymorphic loci, which were used to analyze population's genetics by different methods. At the higher area the plants have greater flowering intensity, the flowers produce less pollen grains and the stigmas receive less pollen, but set more seeds after manual cross pollination than individuals at the lower area, where pollinator diversity is higher and plants produce more fruits. There is genetic differentiation, but also an interface contact between the two populations. The population at higher altitude has less genetic diversity than the one at lower altitude. The lack of pollinators at the higher area is associated with different floral and reproductive strategies to compensate pollen limitation. Moreover the genetic structure and diversity respond to different dynamics of pollen flow and the patterns of distribution and reproduction of Tibouchina pulchra at the altitudinal gradient of Serra do Mar / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal