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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo comparativo do xilema secund?rio de esp?cies de Urbanodendron Mez e contribui??o da anatomia do lenho ? taxonomia da fam?lia Lauraceae Juss / Comparative study of the secondary xylem of Urbanodendron Mez species and contribution of the wood anatomy to the taxonomy of the family Lauraceae Juss

Fernandes, Jo?o Kleber da Costa 29 April 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-03T14:33:01Z No. of bitstreams: 1 2016 - Jo?o Kleber da Costa Fernandes.pdf: 3419179 bytes, checksum: 438592497d93b0e2004465d0aa5c057c (MD5) / Made available in DSpace on 2017-05-03T14:33:01Z (GMT). No. of bitstreams: 1 2016 - Jo?o Kleber da Costa Fernandes.pdf: 3419179 bytes, checksum: 438592497d93b0e2004465d0aa5c057c (MD5) Previous issue date: 2016-04-29 / Lauraceae Juss. is a pantropical and economically important plant family, consisting of 50 genera and approximately 3,000 species, mostly found in humid forests. Several species are important resource in the construction timber, spice, essential oil, and medicinal plants. Among the 22 genera of Lauraceae occurring in Brazil, Urbandodendron Mez. is a genus with three species found in Southeastern Brazil and in Bahia state. Due to the complexity of that group, several classification systems have been proposed to the family. The most recent system suggests the division of the Lauroidea subfamily into three tribes, based on inflorescence morphology and on characters of wood and bark anatomy. On the other hand, Urbanodendron has not been included in that classification, since there are no studies on wood anatomy for that genus up to date. This study aims to provide information that can support Lauraceae taxonomy by describing wood characters of Urbanodendron bahiense (Meisn.) and U. verrucosum (Ness) Mez., followed by a literature review on the wood anatomy of other 21 genera of Lauraceae. Wood samples of both species were collected with an increment borer and processed based on usual techniques of optical and scanning electron microscopy. In order to verify if environmental factors may affect wood structure, samples were collected in Lowland and Submontane Ombrophilous Dense Forest remnants located in two conservation units in Rio de Janeiro state, the Parque Natural Municipal do Curi? and the Reserva Biol?gica de Po?o das Antas. A Principal Coordinates Analysis (PCoA) was used to evaluate how wood anatomy characters may support an intrafamiliar diagnosis in Lauraceae. The comparative analysis between the wood anatomies of U. bahiense e U. verrucosum indicated a homogeneous wood structure for both species, as observed in the other genera of Lauraceae, showing the following wood anatomical characters: growth ring boundaries distinct; porosity diffuse, solitary vessels and radial multiplex of 2-4, circular to oval outline, exclusively simple perforation plates, alternate intervessel pits; septate fibre; axial parenchyma paratracheal vasicentric; uniseriate and multiseriate (2-3 cells) rays; presence of phenolic compounds, mucilage and oil cells. Both species differ only in the location and frequency of oil/mucilage cells. The PCoA showed that wood anatomical characters effectively supported the diagnosis of tribes Cryptocaryeae, Laureae and Perseeae. The structure of the secondary xylem in Urbanodendronhave characters which are common to genera Aniba, Licaria, Nectandra, Ocotea and Persea, all belonging to tribe Perseeae, suggesting the placement of Urbanodendron in that same tribe. There were no quantitative statistically significant differences between cell elements present in individuals from both forest remnants. / Lauraceae Juss. ? uma fam?lia de grande import?ncia econ?mica sendo empregada na culin?ria, na perfumaria e na ind?stria farmac?utica, na fabrica??o de papel, em marcenaria e constru??o civil. As esp?cies t?m distribui??o pantropical, ocorrem nas florestas tropicais e subtropicais, em ambientes ?midos. A fam?lia ? constitu?da por 50 g?neros e aproximadamente cerca de 3.000 esp?cies. No Brasil s?o encontrados 22 g?neros, dentre eles Urbandodendron Mez, constitu?do por tr?s esp?cies, cuja distribui??o est? restrita aos estados do Sudeste e Bahia. Diversas classifica??es foram propostas devido a complexidade do grupo. O sistema de classifica??o mais recente sugere a divis?o da subfam?lia Lauroidea em tr?s tribos baseada na morfologia da infloresc?ncia e na anatomia do lenho e da casca. No entanto, Urbanodendron n?o ? citado nesta classifica??o, devido aus?ncia de estudos sobre a anatomia do lenho para o g?nero, at? o momento. O presente estudo tem como objetivo fornecer subs?dios ? taxonomia de Lauraceae, por meio da descri??o das caracter?sticas do lenho de Urbanodendron bahiense (Meisn.) e U. verrucosum (Ness) Mez, e de uma revis?o sobre a anatomia do lenho de 21 g?neros pertencentes ? fam?lia. Al?m de avaliar se as varia??es ambientais encontradas em Floresta Ombr?fila Densa de terras baixas e submontana promovem mudan?as significativas na estrutura do lenho. As amostras foram coletadas atrav?s de m?todos n?o destrutivos e processadas de acordo com as t?cnicas usuais para observa??o do lenho em microscopia ?ptica e microscopia eletr?nica de varredura. Os indiv?duos provem de duas ?reas de estudo do estado do Rio de Janeiro: O Parque Natural Municipal do Curi? e a Reserva Biol?gica de Po?o das Antas. Para a revis?o foram feitos levantamentos em bases de dados e peri?dicos especializados. A an?lise de coordenadas principais (PCoA) foi utilizada para avaliar como os caracteres anat?micos do lenho podem auxiliar no diagn?stico infrafamiliar em Lauraceae A partir do estudo comparativo da anatomia do lenho de U. bahiense e U. verrucosum foi poss?vel verificar que o lenho apresenta uma estrutura homog?nea como os demais g?neros da fam?lia, que incluem: camadas de crescimento distintas; porosidade difusa, vasos solit?rios e m?ltiplos radiais de 2-4 c?lulas, placa de perfura??o exclusivamente simples e pontoa??es intervasculares alternas; fibras septadas; par?nquima axial paratraqueal vasic?ntrico; raios unisseriados e multisseriados (2-3 c?lulas), integrados por c?lulas procumbentes na por??o central e eretas ou quadradas nas margens; presen?a de subst?ncias fen?licas, c?lulas ole?feras/mucilaginosas associadas ao raio. As esp?cies estudadas diferiram apenas na localiza??o e frequ?ncia das c?lulas ole?feras/mucilaginosas. A an?lise de coordenadas principais mostrou que os caracteres anat?micos do lenho auxiliam no diagn?stico das tribos Cryptocaryeae, Laureae e Perseeae. A estrutura do xilema secund?rio de Urbanodendron apresenta caracteres comuns aos g?neros Aniba, Licaria, Nectandra, Ocotea e Persea que pertencem ? tribo Perseeae, sugerindo o posicionamento do g?nero estudado nessa mesma tribo. A an?lise quantitativa dos elementos celulares encontrados nos indiv?duos de ambas as esp?cies, das duas forma??es vegetais, n?o apresentou diferen?as estat?sticas

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