Morfoanatomia e ontogênese de Machaerium Pers. (Fabaceae: Faboideae): fruto, semente e plântula
Carregando...
Arquivos
Data
2009
Autores
Pinto, Daniela Dias [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Fabaceae apresenta ampla distribuição geográfica e compreende cerca de 727 gêneros e aproximadamente 19.320 espécies, sendo considerada a maior família depois de Asteraceae e Orchidaceae. Faboideae compõe a maior das subfamílias e possui as características mais derivadas. Dalbergieae é uma das tribos basais de Faboideae e apresenta 17 gêneros nos trópicos, concentrados na América tropical; Machaerium está incluído nesta tribo e sendo o maior número de espécies localizadas no Brasil, em diversas formações vegetais. O presente trabalho descreve a morfologia, anatomia e ontogênese dos frutos e sementes de Machaerium brasiliense, M. hirtum, M. nyctitans, M. stipitatum e M. villosum, comparando as espécies entre si e com a literatura; verifica-se, ainda, a morfologia das plântulas de M. brasiliense, M. hirtum e M. villosum, bem como é apresentada a análise anatômica comparada de cotilédones, eofilos e metafilos. O material coletado foi processado segundo técnicas usuais em microscopia de luz, utilizando-se principalmente, inclusão em metacrilato; para estudo da venação, eofilos e metafilos foram diafanizados. As cinco espécies estudadas apresentam o ovário típico das leguminosas, ocorrendo inúmeros tricomas tectores em toda a periferia, além de tricomas glandulares em M. hirtum; o ovário apresenta secção transversal ovada a elíptica, destacando-se a ocorrência de idioblastos fenólicos junto aos feixes vasculares. Após a fecundação, são reconhecidas grandes variações, ocorrendo inúmeras divisões celulares, as quais são mais numerosas no endocarpo externo. Durante a fase de alongamento e diferenciação celulares, destaca-se a formação do seed cushion, constituído por longos tricomas pluricelulares voltados para o interior exceto em M. villosum que o endocarpo interno é parenquimático, formando um tecido que preenche a cavidade seminal...
Fabaceae presents wide geographic distribution and consists of approximately 727 genera and 19,320 species; it has been considered the third largest family, following Asteraceae and Orchidaceae. Faboideae represents the major subfamily and has the most derivative characteristics of such group. Dalbergieae is a basal tribe of Faboideae and presents 17 genera in the tropics, mainly in America; Machaerium is included in that tribe and has the largest number of species located in Brazil, in several biomes. The present work describes the morphology, anatomy and ontogeny of fruits and seeds from Machaerium brasiliense, M. hirtum, M. nyctitans, M. stipitatum, and M. villosum, through comparison between these species and with those in literature; besides, the morphology of seedlings of M. brasiliense, M. hirtum and M. villosum is analyzed and the comparative anatomical analysis of cotyledons, eophylls and metaphylls is presented. The material was collected and processed according to usual techniques of light microscopy, mainly through embedding in methacrylate; for venation study, eophylls and metaphylls were clarified. All studied species have typical leguminous ovary, with several non-glandular trichomes in all periphery, besides glandular trichomes in M. hirtum; the ovary presents ovate to elliptical transverse section, and phenolic idioblasts close to the vascular bundles are also detected. After fecundation, great variations are observed, with several cell divisions, which are more frequent in the outer endocarp. During cell elongation and differentiation, the seed cushion is originated by long pluricellular trichomes directed towards the interior, filling the seed chamber. Lignification is noted in part of the mesocarp and endocarp during fruit ripening, with formation of mesocarpic sclereids and outer endocarp fibers in all species. The samaras present typical structural peculiarities... (Complete abstract click electronic access below)
Fabaceae presents wide geographic distribution and consists of approximately 727 genera and 19,320 species; it has been considered the third largest family, following Asteraceae and Orchidaceae. Faboideae represents the major subfamily and has the most derivative characteristics of such group. Dalbergieae is a basal tribe of Faboideae and presents 17 genera in the tropics, mainly in America; Machaerium is included in that tribe and has the largest number of species located in Brazil, in several biomes. The present work describes the morphology, anatomy and ontogeny of fruits and seeds from Machaerium brasiliense, M. hirtum, M. nyctitans, M. stipitatum, and M. villosum, through comparison between these species and with those in literature; besides, the morphology of seedlings of M. brasiliense, M. hirtum and M. villosum is analyzed and the comparative anatomical analysis of cotyledons, eophylls and metaphylls is presented. The material was collected and processed according to usual techniques of light microscopy, mainly through embedding in methacrylate; for venation study, eophylls and metaphylls were clarified. All studied species have typical leguminous ovary, with several non-glandular trichomes in all periphery, besides glandular trichomes in M. hirtum; the ovary presents ovate to elliptical transverse section, and phenolic idioblasts close to the vascular bundles are also detected. After fecundation, great variations are observed, with several cell divisions, which are more frequent in the outer endocarp. During cell elongation and differentiation, the seed cushion is originated by long pluricellular trichomes directed towards the interior, filling the seed chamber. Lignification is noted in part of the mesocarp and endocarp during fruit ripening, with formation of mesocarpic sclereids and outer endocarp fibers in all species. The samaras present typical structural peculiarities... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Botânica - Morfologia, Botânica, Post-seminal development
Como citar
PINTO, Daniela Dias. Morfoanatomia e ontogênese de Machaerium Pers. (Fabaceae: Faboideae): fruto, semente e plântula. 2009. 92 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2009.