Cultivated tomato plants are extremely susceptible to the two-spotted spider mite Tetranychus urticae Koch. Selection for pest resistance is usually a crucial step required to achieve successful genetic resistance transfer from wild into cultivated tomato genotypes. S. habrochaites LA2329, a wild relative of tomato, is highly resistant to arthropods. Its resistance has been attributed to the presence of a high density of type IV and type VI trichomes and abundant production of 7-epi-zingiberene, a sesquiterpene hydrocarbon. The interspecific backcross hybrids used in this research were derived from the cross between the wild relative tomato, S. habrochaites LA2329, and the cultivated tomato, S. lycopersicum ‘Zaofen 2’ (ZH2). This population has been directly selected for type IV trichome density and zingiberene. The arthropod resistance status of the backcross hybrids was unknown when this research was initiated. Thus, the main objective of the research was to verify the transfer of arthropod resistance from S. habrochaites to cultivated tomato. The effects of glandular trichome densities and leaf zingiberene contents on spider mite behavior and biology were also explored. Also, the chemical composition of the trichome secretions in the wild tomato donor is segregating for presence and abundance of sesquiterpenoids related to zingiberene. The bioactivity of these sesquiterpenoids was explored in this research. To evaluate the relative bioactivities of zingiberene alcohol and 7-epizingiberene, extracted from glandular trichomes of Solanum habrochaites accession LA2329, as well as alpha-zingiberene obtained from ginger oil, these were purified by silica gel chromatography and bioassayed with two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae) using a bean leaf disc bioassay. Zingiberene alcohol was most efficacious and alpha-zingiberene, was least efficacious, while the efficacy of 7-epizingiberene was intermediate. Thus, tomato breeders should consider introgression of the genes responsible for the oxidation of 7-epizingiberene into zingiberene alcohol to potentially improve the spider mite resistance of cultivated tomato. Also, it is possible that this compound may be exploited as eco-biopesticide approach for integrated pest management against a broad spectrum of herbivorous pests. To verify transfer of arthropod resistance, a bioassay utilizing whole leaves was employed. Nine hybrids (BC3F3 and BC3F4) were chosen for this bioassay, based on variation of type IV trichome density and zingiberene concentration among the hybrids. The experiment also included three susceptible and three resistant control plants. Mite responses on some of the hybrids were similar to those on the resistant wild donor parent, S. habrochaites, as indicated by number of leaflet surfaces infested by mites, degree of mite webbing and feeding damage. Egg density on four backcross hybrids was similar to that on the S. habrochaites resistant controls. Based these results, we concluded that resistance had been successfully transferred from the wild accessions to the hybrids by deployment of backcrossing and indirect selection. There was a significant negative correlation of almost all mite behavioral and biological responses with Type IV trichome density and zingiberene content. This bioassay illuminated behavioral variations of mites associated with presence or absence of leaf compounds and glandular trichome densities. Also, the results support the idea that introgression of type IV trichomes and zingiberene has led to effective spider mite resistance. In another bioassay-based experiment to verify transfer of resistance, seven interspecific backcross hybrids (BC3F2), the resistant parent LA2329, and two susceptible cultivated tomato lines, the recurrent parent ZH2 and ‘Small Roma’, were used in thumbtack bioassays. Mite movement was measured by imaging bioassayed leaves at 15, 20, 30, 45, and 60 min intervals. In addition to confirming transfer of spider mite resistance, other objectives included determination of the relative contributions of type IV and VI trichome densities and leaf compounds to mite behavior over time intervals. Our findings confirmed the transfer of mite repellency from the wild resistant parent to advanced backcross hybrids. Several backcross hybrids performed similarly to the wild donor parent, displaying shorter distances traveled on the leaves after 15 and 30 min. The type IV and type VI trichome densities as well as zingiberene contents had a significant positive correlation with the number of spider mites remaining on tack. There was a significant negative correlation of type IV density and zingiberene concentration with the total distance travelled by mites for both the abaxial and adaxial surfaces across most time intervals. Stepwise multiple regression analysis showed that the type IV trichome density was the most critical factor, and zingiberene content was a secondary factor across over most time intervals. T. urticae remained longer on the thumbtack heads and traveled shorter distances on the leaf surface of the wild donor parent LA2329 and the interspecific hybrids compared to S. lycopersicum leaves. These results indicated that introgression of genetic resistance, especially repellence, against spider mite from the wild relative into cultivated tomato varieties has been successfully achieved. In conclusion, trichome type IV and/or zingiberene content has been successfully transferred from the wild relative into interspecific tomato hybrids, and the hybrids show significant adverse impact on spider mite behavior and/or biology in whole leaf and thumbtack bioassays. Type IV trichome density is the most crucial factor in mite deterrence while zingiberene seemed to be a second key factor across most of time durations for both surfaces. Collectively, several backcross hybrids had similar leaf characteristics to the S. habrochaites LA2329, also may be a potential source of resistance to other insect pests.

Studies on epidermal cell fate determination have been important for gaining insight into the genetic and molecular mechanisms leading to the differentiation and patterning of cells. In Arabidopsis, the organization and development of many epidermal characters including trichomes, root hairs and the seed coat have been found to be controlled by a single combinatorial transcription factor complex consisting of a WD-repeat containing protein, Transparent Testa Glabra 1 (TTG1), and various MYB and bHLH proteins. The work here consists of identification of Glabra2 (GL2) and Transparent Testa Glabra2 (TTG2) as direct transcriptional targets of the TTG1 combinatorial complex, further characterization of GL2 function, and identification of transcriptional targets of GL2 and TTG2. Both GL2 and TTG2 are important in the regulation of trichomes, root hairs and seed coat development. vii GL2 has been identified as an important regulator of epidermal cell fate for over fifteen years yet there is little known about its function and only three transcriptional targets are identified, all involved in root hair patterning. Through the examination of its function a nuclear localization signal was verified and shown that GL2 homodimerizes. Through analysis of available expression databases and differential sequence analysis using SOLiD sequencing technology, several direct targets of GL2 and many more possible transcriptional targets of both GL2 and TTG2 were identified in trichomes. Some of these targets are members of the TTG1 complex, and they are all specialized in the maturation of trichomes, suggesting that GL2 switches the focus of the complex by activating the TTG1 complex members involved in maturation of the trichome through a feedback mechanism. Examination of gl2 mutants shows that they do not produce trichome accessory cells which usually surround the trichome. An additional target of GL2 is At5g65300 which when overexpressed results in the elongation and proliferation of trichome accessory cells into a tall pillar of cells. This suggests that GL2 is involved in the regulation of accessory cell development through At5g65300. The work presented here represents important advances of our knowledge of epidermal cell fate through characterization of the major downstream regulators of epidermal development. / text

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 5 uppsatser.

The plant Urera baccifera Gaudich, known as stinging nettle, had its leaves and roots used to urinary infections and arthritis. Studies about its anti-inflammatory activities already exist, but are few the studies about their chemical constituents. Due the shortage of dates, this study aim to realize an qualitative and quantitative photochemistry analysis, and antioxidant activity of the plant roots and leaves, beyond realize a morphoanatomic and hystochemical study its leaves and stems. In the qualitative analysis were obtained positive results to aminogroups, anthocyanins, anthocyanidins and flavonoids, steroids, phenols with free para positions, coumarins, saponins and organic acids in the leaves and the roots. In the qualitative analysis the plant showed significant values of phenolic compounds, flavonoids, alkaloids and condensed tannins, mainly in the chloroform fraction of leaves and roots. The crude extract of both part of the plant presented a moderated antioxidant activity. An expressive concentration of oxalic acid was quantified in the roots, indicating toxicity. The morphological analysis of steams and leaves showed stinging, simple tectores and glandular trichomes, cistolits in the epidermis and abundant presence of drusen-type crystals of calcium oxalate besides that elucidate the inner structure of the plant tissues. In the hystochemical tests were presented in the different vegetative organs, substances which form cell walls, reserve substances and secondary metabolites, like phenolic compounds, lipids, terpenoids and cetosteroids, tannins and serotonin. More studies will be realized with Urera baccifera roots, stems and leaves, to elucidate its chemical composition and toxic potential. / A planta Urera baccifera Gaudich, conhecida como Urtiga-Brava, tem suas folhas e raízes utilizadas para infecção urinária e artrite. Já existem estudos sobre sua atividade antiinflamatória, mas poucos são os estudos a respeito de sua composição química. Devido à escassez de dados, este estudo visa realizar uma análise fitoquímica qualitativa e quantitativa, e avaliar a atividade antioxidante das raízes e folhas da planta, além de realizar um estudo morfo-anatomico e histoquímico das folhas e caules. Na análise qualitativa foram obtidos resultados positivos para aminogrupos, antocianinas, antocianidinas e flavonóides, esteróides, fenóis com posição para livres, cumarinas, saponinas e ácidos orgânicos nas folhas e raízes. Na analise qualitativa a planta mostrou valores significantes de compostos fenólicos, flavonoides, flavonóis, alcaloides e taninos condensados principalmente na fração clorofórmio das folhas e raízes. O extrato bruto das duas partes da planta demonstraram uma moderada atividade antioxidante. Foi quantificado numa concentração expressiva, ácido oxálico nas raízes, indicando toxicidade. A análise da morfologia dos caules e folhas evidenciou tricomas urticantes, tectores simples e glandulares, cistólitos na epiderme e presença abundante de cristais do tipo drusas de oxalato de cálcio, além de elucidar a estrutura interna dos tecidos da planta. Nos testes histoquímicos foram evidenciados nos diferentes órgãos vegetativos, substâncias que formam as paredes celulares, substâncias de reserva e metabólitos secundários, como compostos fenólicos, lipídios, terpenóides e cetoesteróides, taninos e serotonina. Mais estudos serão realizados com raízes, caules e folhas de Urera baccifera, a fim de elucidar sua composição química e analisar seu potencial tóxico.

Made available in DSpace on 2014-06-11T19:23:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-27Bitstream added on 2014-06-13T18:09:25Z : No. of bitstreams: 1 favorito_s_me_botib.pdf: 3482057 bytes, checksum: 9452eeacdb2dbcd0bcc50af6cce2af92 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Uma característica da família Verbenaceae é a presença de tricomas secretores, geralmente produtores de óleos essenciais de grande valor medicinal. Muitas espécies de Lippia Houst. são utilizadas em programas fitoterápicos e de complementação alimentar no Brasil, sendo L. alba e L. sidoides as mais utilizadas e estudadas. O cerrado possui aproximadamente 33 espécies de Lippia cujo potencial farmacológico é desconhecido. Apesar da importância econômica como fonte de medicamentos e da representatividade de Lippia na flora aromática nativa, pouco se conhece sobre os aspectos estruturais e da secreção dos seus tricomas secretores. Neste trabalho foram estudados os tricomas secretores presentes em órgãos vegetativos e reprodutivos de L. stachyoides Cham. sob o ponto de vista morfológico, ontogenético, histoquímico e ultra-estrutural. Foram utilizadas técnicas convencionais em estudos anatômicos e ultra-estruturais; a identificação in situ da composição química das substâncias presentes nos tricomas foi realizada por meio de testes histoquímicos. Em L. stachyoides, os tricomas secretores são capitados e foram classificados em cinco tipos morfológicos, os quais são amplamente distribuídos no caule, folhas e inflorescências. A histoquímica revelou que nos tipos I e IV predominam substâncias hidrofílicas e nos tipos II e V, substâncias lipofílicas. De um modo geral, as características ultraestruturais observadas em cada tipo de tricoma corroboraram os resultados das análises histoquímicas. Os resultados do presente trabalho sugerem que as variações morfológicas dos tricomas secretores em L. stachyoides estão associadas com a composição química da secreção / A feature of the family Verbenaceae is the presence of secretory trichomes, producers of essential oils with great medicinal value. Many species of Lippia Houst. are employed in phytotherapic and food complementation programs in Brazil, being L. alba and L. sidoides the most employed and studied species. The Brazilian cerrado has approximately 33 species of Lippia, whose pharmacological potential is unknown. Despite the economic importance of Lippia as a source of medicinal drugs and its representation in native aromatic flora, little is known about the structural and secretion features of its trichomes. In this work, the secretory trichomes, occurring in vegetative and reproductive organs of Lippia stachyoides Cham., were studied on the morphological, ontogenetic, histochemical and ultrastructural views. Usual techniques of vegetal anatomy and ultrastructure were employed; in situ identification of the chemical composition of the substances present in the trichomes was performed according to histochemical tests. In L. stachyoides, the secretory trichomes are capitate and classified according to five morphological types which are widely distributed in the shoot, leaves and inflorescences. The histochemistry revealed that in types I and IV, hydrophilic compounds are predominant and that lipophilic substances predominate in the types II and V. In general, the ultrastructural features observed in each trichome type corroborate the histochemical analysis. The results of this work suggest that morphological variations of secretory trichomes in L. stachyoides are associated to the chemical composition of the secretion

Submitted by PATRICE JACOB SAVI (savipatricejacob@yahoo.fr) on 2018-04-13T23:56:05Z No. of bitstreams: 1 Savi_pj_me_jabo.pdf: 5321539 bytes, checksum: 55c0543813b08023f4e1f48c3330cf33 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-16T10:40:16Z (GMT) No. of bitstreams: 1 savi_pj_me_jabo.pdf: 5321539 bytes, checksum: 55c0543813b08023f4e1f48c3330cf33 (MD5) / Made available in DSpace on 2018-04-16T10:40:16Z (GMT). No. of bitstreams: 1 savi_pj_me_jabo.pdf: 5321539 bytes, checksum: 55c0543813b08023f4e1f48c3330cf33 (MD5) Previous issue date: 2018-02-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O ácaro-vermelho-do-tomateiro, Tetranychus evansi Baker e Pritchard (Acari: Tetranychidae), foi introduzido em diversos países da África e da Europa a partir da América do Sul. Nesses países, este ácaro encontrou condições favoráveis ao seu desenvolvimento e se tornou uma das principais pragas do tomateiro, podendo causar perdas de produtividade de até 90%. Devido ao seu elevado potencial biótico, o controle desse ácaro é dificultado pela baixa eficiência dos produtos empregados e pelas populações resistentes aos acaricidas. Dessa forma, o uso de plantas resistentes se torna essencial como uma alternativa ideal de controle, uma vez que permite a manutenção da praga em níveis inferiores aos de dano econômico, minimizando o impacto ambiental do uso de acaricidas e diminuindo os custos de produção. Diante disto, o objetivo deste trabalho foi selecionar genótipos de tomateiro provenientes da África que confiram resistência ao ácaro T. evansi utilizando os genótipos sul americanos de tomateiros selvagens como testemunha. Foram avaliados cinco genótipos de tomateiros comerciais Solanum lycopersicum L. oriundos do Institut National des Recherches Agricoles du Bénin (INRAB), sendo var. AKIKON, var. TOUNVI, var. KEKEFO oriundos do Benin, var. TOML4 oriundo do Senegal, var. TLCV15 oriundo da República Democrática de Congo, e os genótipos selvagens sul americanos: Solanum pennellii Correll LA-716 e Solanum habrochaites Knapp e Spooner var glabratum (PI134417 e PI134418) oriundos do Instituto Agronômico de Campinas, SP-Brasil. Foram realizados experimentos de preferência para atratividade e para o oviposição com chance e sem chance de escolha em laboratório, assim como a relação com a densidade de tricomas foliares com a preferencia do ácaro foram realizados. Foi realizado também um experimento de resistência por antibiose mediante a duração dos estádios de desenvolvimento, oviposição, viabilidade de ovos, sobrevivência nesses genótipos mantidos em câmara climatizada. Os genótipos de tomateiro africanos (AKIKON, TOUNVI, KEKEFO, TOML4 e TLCV15) possuem maior densidade de tricomas não glandulares especialmente o tipo Va, o que proporcionou maior preferência para atratividade e oviposição do ácaro T. evansi ao comparar com os resultados dos genótipos sul americanos de tomateiros (LA-716 e PI134417). Nenhum dos genótipos africanos testados apresentou resistência por antibiose. De acordo com nível de resistência dos genótipos testados porém, os selvagens da América do Sul (PI134417 e PI134418) foram altamente resistentes ao ácaro, os genótipos de tomateiro africanos TLCV15 e TOML4 foram moderadamente resistentes, enquanto AKIKON foi suscetível e os genótipos TOUNVI e KEKEFO foram altamente suscetíveis ao ácaro vermelho. / The tomato red spider mite Tetranychus evansi Baker and Pritchard (Acari: Tetranychidae) was introduced in several countries of Africa and Europe from South America. In these countries, this mite found favorable conditions for its development and becomes one of the main pests of tomato, which can cause yield losses of up to 90%. Due to its high biotic potential, the control of this mite is dificultated by the low efficiency of the chemicals used and populations resistant to acaricides. Thus, the use of resistant plants becomes essentials as an ideal control alternative, since it allows the pest to be kept at levels below the economic threshold, minimizing the environmental impact of the use of acaricides and reducing production costs. Therefore, the aim of this study was to select African tomato genotypes that confers resistance to red spider mite using the South American tomato genotypes as a control. Five commercial tomato genotypes of Solanum lycopersicum L. from Institut National des Recherches Agricoles du Bénin (INRAB) were evaluated: var. AKIKON, var. TOUNVI, var. KEKEFO from Benin, var. TOML4 from Senegal, var. TLCV15 from the Democratic Republic of Congo, and two wild tomato genotypes from South America: Solanum pennellii Correll LA-716 and Solanum habrochaites Knapp & Spooner f. glabratum (PI134417 and PI134418) from the Instituto Agronômico de Campinas, SP, Brasil. No-preference bioassay for attractiveness and oviposition was conducted in free choice and no choice tests as well as the relationship of the density of leaf trichomes with the preference of the red spider mite were realized. It was also carried out the antibiosis resistance bioassay evaluating immature development time, oviposition rate, egg viability and survival of T. evansi in these genotypes maintened under controlled laboratory conditions. African tomato genotypes (AKIKON, TOUNVI,KEKEFO, TOML4 e TLCV15) have a higher density of non - glandular trichomes especially type Va, which provided higher attractiveness preference and oviposition of the T. evansi mite when compared to the results of the South American (LA-716 and PI134417) tomato genotypes. None of the African tomato genotypes tested showed antibiosis resistance. According to the resistance level of the genotypes tested, South American tomato genotypes PI134417 and PI134418 were highly resistants to the red spider mite, African tomato genotypes TLCV15 and TOML4 were less suitables hosts for T. evansi, while AKIKON was suitable host and TOUNVI and KEKEFO were most suitable hosts for red spider mite. / CNPQ- PEC-PG: 190160/2015-2

Duas espécies de Barbatimão, da família Leguminosae, foram utilizadas como modelo neste trabalho para elucidar as vias ontogenéticas de produção de taninos: Dimorphandra mollis Benth. (Caesalpinioideae) e Stryphnodendron adstringens (Mart.) Coville (Mimosoideae). Apesar de inseridas em grupos distantes de Leguminosae, as duas espécies são grandes produtoras de taninos, geralmente concentrados na casca, o que confere a elas uma grande procura para uso na medicina popular. Partes vegetativas de Indivíduos jovens e adultos foram processadas para observações em microscopia de luz e eletrônica (varredura e transmissão). Dois tipos de estruturas secretoras são responsáveis pela produção e acúmulo de taninos: idioblastos, encontrados já em indivíduos jovens de ambas espécies; e tricomas secretores, encontrados em gemas vegetativas de indivíduos adultos de S. adstringens. O processo de produção de taninos nas duas espécies é semelhante, com alguma diferença nas etapas de acúmulo. Plastídios e RER parecem ser as organelas associadas à produção de taninos nessas espécies. Destaca-se ainda o relato inédito da ocorrência de coléteres de origem protodérmica em D. mollis. Considerando a problemática referente à classificação de estruturas secretoras, pretende-se utilizar os resultados obtidos para reflexão sobre o tema / In this study, two species of Leguminosae, popularly known as Barbatimão, were used as a model to elucidate the ontogenetic process of tannin production: Dimorphandra mollis Benth. (Caesalpinioideae) and Stryphnodendron adstringens (Mart.) Coville (Mimosoideae). Although inserted in non-related groups of Leguminosae, the two species are largely known as tannin producers, a metabolite often concentrated in the bark, which makes them highly sought after for use in folk medicine. Vegetative parts of young and adult plants were processed for observation using light and electron microscopy (scanning and transmission). Two types of secretory structures are responsible for tannin production and accumulation: idioblasts, found even in young plants of both species, and secretory trichomes, observed in vegetative buds of mature plants of S.adstringens. Tannin production is similar in both species, although some differences in the stages of accumulation occur. Plastids and RER organelles appear to be associated with the production of tannins in these species. This study also provides the first report of colleters in D. mollis, which originate from protodermal cells. Considering the controversies regarding the classification and nomenclature of secretory structures, our results can be used to help clarify some issues regarding secretory structures, especially colleters

Orientadores: Ana Maria Goulart de Azevedo Tozzi, Marcelo Fragomeni Simon / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T15:05:10Z (GMT). No. of bitstreams: 1 Silva_JulianaSantos_D.pdf: 25543096 bytes, checksum: b9b00812e9badd64c99e92212fb2b35a (MD5) Previous issue date: 2013 / Resumo: Mimosa L. é o segundo maior gênero de Mimosoideae, com distribuição pantropical e mais de 500 espécies. Entre as cinco seções do gênero, Mimosa sect. Batocaulon DC., com 190 espécies, é uma das seções mais diversificadas morfologicamente. Dentre as suas 25 séries, Mimosa ser. Leiocarpae Benth. é a maior, com 31 espécies distribuídas principalmente nos ambientes xéricos sulamericanos. Caracteriza-se pelos diferentes tipos de tricomas e pelas flores tetrâmeras, diplostêmones agrupadas em espigas. Muitas das suas espécies são mal definidas, o que é agravado pela ausência de ilustrações para maioria delas e pela escassez de coleta de alguns táxons. Estudos filogenéticos moleculares têm sustentado o monofiletismo de Mimosa, mas têm demonstrado que suas categorias infragenéricas, precisam de melhor esclarecimento, haja vista o seu para- ou polifiletismo. O objetivo deste trabalho foi a realização de estudos filogenéticos, micromorfológicos e a revisão taxonômica de M. ser. Leiocarpae, visando contribuir com taxonomia e a delimitação desse grupo. O estudo filogenético baseou-se em marcadores moleculares derivados do DNA do nuclear (ITS) e do cloroplasto (matK/trnK, trnD-trnT e trnL-trnF), analisadas através dos métodos de máxima parcimônia e análise Bayesiana, enquanto que os estudos taxonômicos revisionais e micromorfológicos fundamentaram-se nos procedimentos taxonômicos e micromofológicos tradicionais, respectivamente. No capítulo 1, que trata da filogenia de M. ser. Leiocarpae, as análises cladísticas mostraram que a ser. Leiocarpae é polifilética, sendo representada por três distintas linhagens. Com estes resultados, houve a necessidade de se propor a sua re-circunscrição, aceitando cinco das 31 espécies incluídas na M. ser. Leiocarpae, juntamente com espécies de Mimosa ser. Bimucronatae Barneby e M. ser. Farinosae Barneby. O capítulo 2 traz o estudo micromorfológico dos diferentes tipos de tricomas de Mimosa, com enfâse nas espécies de M. ser. Leiocarpae, grupo que exibe uma grande diversidade de tricomas. A morfologia dos tricomas de 35 espécies foi estudada usando microscopia ótica e microscopia eletrônica de varredura com objetivo de esclarecer a terminologia tradicionalmente usada e testar hipóteses evolutivas. Dois tipos de tricomas foram reconhecidos: glandular e não glandular. Os tricomas glandulares podem ser sésseis ou estipitados, enquanto os não gladulares podem ser ramificados (barbados, estrelados, estrelado-lepidotos, lepidotos, plumosos e verruciformes) ou não. Tricomas glandulares e não glandulares evoluíram independentemente em diferentes linhagens em Mimosa, corroborando, em geral, as hipóteses sobre a evolução dos tricomas de Barneby (1991). O capítulo 3 trata do estudo palinológico das espéceis de M. ser. Leiocarpae e suas implicações na filogenia e taxonomia do grupo (Santos-Silva et al. 2013a). Os grãos de pólen são agrupados em tétrades ou ditétrades. A morfologia do pólen não sustenta a monofiletismo de M. ser. Leiocarpae, apoiando as evidências trazidas pelos estudos filogenéticos moleculares. No capítulo 4 é apresentada a revisão das espécies de M. ser. Leiocarpae sensu Barneby (1991). Foram propostas 11 novas sinonimizações, uma lectotipificação, um novo status, além disso, foram complementadas a descrição original de três espécies e registradas quatro novas ocorrências para a América do Sul. No anexo encontra-se a descrição uma nova espécie de Mimosa (Santos-Silva et al. 2013b) / Abstract: Mimosa L. is a pantropical genus with more than 500 species, making it the second largest genus of subfamily Mimosoideae. Of the five currently recognized sections of the genus, Mimosa sect. Batocaulon DC. is one of the largest and morphologically most diverse, comprising ca. 190 species. Among the 25 currently recognized series within sect. Batocaulon, Mimosa ser. Leiocarpae Benth. is the largest, comprising 31 species mainly distributed in xeric habitats of South America. It is characterized by the presence of specialized trichomes and by the spikes of tetramerous, diplostemonous flowers. Many of its species are poorly defined, and this was exacerbated by the lack of illustrations for the majority of the species and by the scarcity of collections of some taxa. Molecular phylogenetic studies have supported the monophyly of Mimosa, but they have demonstrated that its infrageneric groups are para- or polyphyletic. The objective of the present work was to conduct a phylogenetic, micromorphologic studies and taxonomic revision of M. ser. Leiocarpae, as a contribution towards its taxonomy and delimitation. The phylogenetic study was based on molecular markers obtained from nuclear (ITS) and chloroplast DNA (matK/trnK, trnD-trnT and trnL-trnF) DNA, analyzed using parsimony and Bayesian methods; the taxonomic and micromorphologic studies were based on traditional methods. In Chapter 1, concerning the phylogeny of M. ser. Leiocarpae, the analyses showed that the group is polyphyletic, and is represented by three distinct lineages. These results demanded a revised circumscription of M. ser. Leiocarpae that recognizes five of the 31 species traditionally included in the group and three more species from Mimosa ser. Bimucronatae Barneby and M. ser. Farinosae Barneby. Chapter 2 is a micromorphological study of the trichome types observed in Mimosa, with emphasis on the species of ser. Leiocarpae, which exhibits notable diversity of trichomes. The leaf trichomes of 35 species were examined using optical and scanning electron microscopes, with the objective of clarifying the traditional terminology for describing these trichome types and for testing hypotheses regarding their evolution. Two basic types of trichomes were recognized, glandular and non-glandular. The glandular trichomes can be sessile or stipitate, while the non-glandular trichomes can be branched (barbate, stellate, lepidote-stellate, lepidote, plumose, and verruciform) or unbranched. Glandular and non-glandular trichomes evolved independently in different lineages of Mimosa, essentially corroborating current hypotheses on trichome evolution by Barneby (1991). Chapter 3 is a palynological study of the species of M. ser. Leiocarpae and of the implications for the taxonomy of the group (Santos-Silva, 2013a). Pollen grains are arranged in tetrads of ditetrads, the latter decussate, isopolar or heteropolar, compressed or not, the outline elliptic or ellipsoid. The results of the pollen morphology do not support the monophyly of M. ser. Leiocarpae s.l., corroborating evidences from molecular phylogenetic studies. Chapter 4 is a revision of M. ser. Leiocarpae s.l.. In this chapter proposed eleven new synonymies, one lectotypification, and one new status. Three species descriptions are emended, and four new geographic records are reported for South America. Annex consist of already published article that describe one new species in Mimosa (Santos-Silva et al. 2013b) / Doutorado / Biologia Vegetal / Doutora em Biologia Vegetal

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Bromeliaceae ocupa posição basal na Ordem Poales e é considerada monofilética, tendo sinapomorfias morfológicas e moleculares. Atualmente é subdividida em oito subfamílias, sendo Bromelioideae a subfamília com maiores problemas na delimitação genérica. Nesse contexto encontra-se o Complexo Nidularióide, formado pelos gêneros Nidularium Lem., Wittrockia Lindm., Neoregelia L.B.Sm., Canistropsis (Mez) Leme e Edmundoa Leme. A dificuldade na delimitação destes gêneros se dá pelo uso de um grande número de caracteres não exclusivos, que mostram o íntimo relacionamento entre estes gêneros. Embora estes gêneros não sejam monofiléticos, como indicam as filogenias recentes, o Complexo Nidularióide como um todo sempre emerge em um clado, indicando que formam uma unidade taxonômica. Neste contexto, analisamos caracteres morfológicos e anatômicos a fim de estabelecer novas sinapomorfias para o Complexo. Nossos resultados indicam que os principais caracteres morfológicos utilizados na delimitação dos gêneros do complexo Nidularióide são homoplásticos. A maior parte dos caracteres anatômicos também representam homoplasias. No entanto a anatomia foliar mostrou-se útil, provendo novas sinapomorfias para o grupo, tais como a presença de células da ala alongadas nos tricomas, e presença de células epidérmicas adaxiais com paredes levemente espessadas na lâmina foliar. No segundo capítulo, analisamos a anatomia floral de 16 espécies de Bromeliaceae, pertencente a três das oito subfamílias, a fim de estabelecer caracteres anatômicos florais úteis na sistemática do grupo, bem como discuti-los sob uma perspectiva ecológica e filogenética. Uma nova sinapomorfia é proposta para Pitcairnoideae a partir de dados sobre a vascularização do gineceu. No terceiro capítulo, analisamos o desenvolvimento foliar de três espécies de Tillandsia L. (Tillandsoideae). Neste estudo, foi possível registrar a presença de coléteres nas bainhas foliares próximas aos ápices caulinares de T. tricholepis (L.) L. Estas estruturas são responsáveis pela proteção do meristema apical caulinar (MAC) por meio de seu exsudado. Este estudo é o primeiro registro destas estruturas em Bromeliaceae / Bromeliaceae ocupies a basal position in Poales Order and is considered monophyletic by morphological and molecular sinapomorphies. The family is currently subdivided into eight subfamilies. Bromelioideae has major problems in generic delimitation. In this context is included Nidularioid Complex, formed by the genera Nidularium Lem., Wittrockia Lindm., Neoregelia L.B.Sm., Canistropsis (Mez) Leme e Edmundoa Leme. The difficulty to generic delimitation in these genera occurs by the presence of a great number of non-exclusive character, which demonstrates their intimate relashioship. Although recent phylogenies indicate these genera are not monophyletic, Nidularioid Complex always emerges as a clade, which suggests they are a true taxonomic entity. In this context, we analyzed morphological and anatomical characters to establish new sinapomorphies for the Complex. Our results indicates that the main morphological characters used in genera delimitation on Nidularioid Complex are homoplastic. The major part of anatomical characters are also homoplastic. However, leaf anatomy shows to be useful, providing new synapomorphies for this group, such as the presence of trichomes with elongated wing\'s cells and the presence of adaxial epidermal cells with lightly thickened walls on leaf blade. On the second chapter, we analyzed floral anatomy of 16 species of Bromeliaceae, belonging to three out of eight subfamilies, to establish anatomical floral characters useful in the group sistematics, as well as discuss it under an ecological and phylogenetic perspective. A new synapomorphy for Pitcairnoideae is established, by data of gynoicea vascularization. On the third chapter, we analyzed leaf development of three species of Tillandisia L. (Tillandsoideae). In this study, it was possible to describe the presence of colleters in leaf sheath, next to shoot apices of T. tricholepis (L.) L. These structures are responsible by shoot apical meristem\'s (SAM) protection by their secretion. This is the first record of colleters in Bromeliaceae