Morfoanatomia do fruto, semente e plântulas de Acalypha gracilis (Spreng.) Müll. Arg., Euphorbia cotinifolia L. e Jatropha gossypiifolia L. (Euphorbiaceae)
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Data
2012-08-14
Autores
Oliveira, Jonathas Henrique Georg de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho descreve aspectos morfológicos e anatômicos, além do desenvolvimento ontogenético dos frutos, sementes e plântulas de Acalypha gracilis, Euphorbia cotinifolia e Jatropha gossypiifolia, Euphorbiaceae, subfamílias Acalyphoideae, Euphorbioideae e Crotonoideae, respectivamente. Os frutos são deiscentes, com deiscência explosiva para liberação das sementes que são elípticas ou globosas, anátropas, albuminosas, exotégmicas (camada mecânica formada por células alongadas, de paredes espessadas, lignificadas) e, as de J. gossypiifolia são endopaquicalazais. O pericarpo foi descrito em quatro estágios: I- ovário, II- fruto com intensa atividade meristemática, III- frutos jovens até seu tamanho definitivo e IV- amadurecimento e lignificação do estrato esclerenquimático. Ovário trilocular típico de Euphorbiaceae foi encontrado nas três espécies, com um óvulo em cada lóculo. No estágio I, ocorreram intensas divisões por toda estrutura do ovário. No estágio II, evidenciaram-se vários feixes vasculares laterais e, na porção mais interna do mesocarpo mediano, as células são alongadas radialmente, e no endocarpo divisões periclinais, exceto em A. gracilis. No estágio III, as células aumentaram de volume, e iniciou-se a diferenciação do estrato esclerenquimático, na porção interna do fruto. No estágio IV ocorreu a lignificação do estrato, início de espaços intercelulares e desidratação do pericarpo para o processo de deiscência. As sementes são elípticas ou globosas, anátropas, albuminosas, exotégmicas (camada mecânica formada por células alongadas, de paredes espessadas, lignificadas) e, as de J. gossypiifolia são endopaquicalazais. Os embriões encontrados são espatulados com eixo hipocótilo-radícula curto e cônico, cotilédones largos e foliáceos, plúmula indiferenciada e endosperma... 9Resumo completo, clicar acesso eletrônico abaixo)
The present work describes morphological and anatomical aspects, and the ontogeny of fruits, seeds and seedlings of Acalypha gracilis, Euphorbia cotinifolia and Jatropha gossypiifolia, members of Euphorbiaceae, subfamilies Acalyphoideae, Euphorbioideae and Crotonoideae, respectively. They fruits present explosive dehiscence to release its seeds, which are elliptical or globose, anatropous, albuminous and in the case of J. gossypiifolia, endopachichalazal. In the pericarp observations, it can be described, from the perspective of four stages: I – ovary, II – fruit with intense meristematic activity, III – young fruits until their definitive size and IV – maturity and lignification of the sclerenchymatous stratum. Typical Euphorbiaceae ovary is found in three species with one ovule in each locule of the trilocular ovary. In stage one, there are intense divisions throughout the ovary structure; in stage II, there are several lateral bundles and the inner portion of the median mesocarp is displayed a layer of radially elongated cells and periclinal divisions in the core, with the exception of A. gracilis. In the stage III, the cells increase the volume and the differentiation of sclerenchymatous stratum starts. In stage IV, lignification occurs in the stratum, as well as the beginning of the intercellular spaces, and dehydration of the pericarp so that the dehiscence process occurs. All seeds are exotégmics due to lignification and differentiation of the exotegmen, being formed by anticlinally elongated cells, very thick walls and curves. Seminal wrap is thick and stiff. There is presence of endopachichalaza in J. gossypiifolia seed, characterized by the beam penetration in the rafeal chalaza and branching out internally in the inner integument. The found embryos are as the ones described for the family, with short and conical... (Complete abstract click electronic access below)
The present work describes morphological and anatomical aspects, and the ontogeny of fruits, seeds and seedlings of Acalypha gracilis, Euphorbia cotinifolia and Jatropha gossypiifolia, members of Euphorbiaceae, subfamilies Acalyphoideae, Euphorbioideae and Crotonoideae, respectively. They fruits present explosive dehiscence to release its seeds, which are elliptical or globose, anatropous, albuminous and in the case of J. gossypiifolia, endopachichalazal. In the pericarp observations, it can be described, from the perspective of four stages: I – ovary, II – fruit with intense meristematic activity, III – young fruits until their definitive size and IV – maturity and lignification of the sclerenchymatous stratum. Typical Euphorbiaceae ovary is found in three species with one ovule in each locule of the trilocular ovary. In stage one, there are intense divisions throughout the ovary structure; in stage II, there are several lateral bundles and the inner portion of the median mesocarp is displayed a layer of radially elongated cells and periclinal divisions in the core, with the exception of A. gracilis. In the stage III, the cells increase the volume and the differentiation of sclerenchymatous stratum starts. In stage IV, lignification occurs in the stratum, as well as the beginning of the intercellular spaces, and dehydration of the pericarp so that the dehiscence process occurs. All seeds are exotégmics due to lignification and differentiation of the exotegmen, being formed by anticlinally elongated cells, very thick walls and curves. Seminal wrap is thick and stiff. There is presence of endopachichalaza in J. gossypiifolia seed, characterized by the beam penetration in the rafeal chalaza and branching out internally in the inner integument. The found embryos are as the ones described for the family, with short and conical... (Complete abstract click electronic access below)
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Plant anatomy, Euforbiacea, Botânica - Morfologia, Ontogenia, Endosperma, Pericarpo (Botânica), Mudas, Anatomia vegetal
Como citar
OLIVEIRA, Jonathas Henrique Georg de. Morfoanatomia do fruto, semente e plântulas de Acalypha gracilis (Spreng.) Müll. Arg., Euphorbia cotinifolia L. e Jatropha gossypiifolia L. (Euphorbiaceae). 2012. 88 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2012.