Morfoanatomia do pericarpo, semente, folha de Psychotria hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg. e Psychotria trichophora Müll. Arg., e desenvolvimento morfológico da plântula de Psychotria hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg. (Rubiaceae, Rubioideae, Psychotrieae)
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Data
2008-05-26
Autores
Pietrobom, Rita de Cássia Violin [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Psychotria é o gênero maior de Rubiaceae. Representado mundialmente por cerca de 1.000 espécies é considerado taxonomicamente complexo devido ao seu tamanho e a ausência de caracteres morfológicos disponíveis para a definição dos grupos. Foram estudados aspectos estruturais do pericarpo, da semente, das folhas de Psychotria hoffmannseggiana e Psychotria trichophora e da plântula de Psychotria hoffmannseggiana. A estrutura e o desenvolvimento do pericarpo e da semente das espécies estudadas são semelhantes. O estádio I do desenvolvimento do fruto é representado pelo ovário de botões florais e de flores em pré-antese. O ovário é ínfero, bicarpelar, bilocular com um óvulo por lóculo, e a placentação é axial basal. A semente é originada do óvulo anátropo e unitegumentado. No estádio II, ocorre o predominio de atividade meristemática no pericarpo (mesocarpo e endocarpo) e no tegumento da semente. O estádio III é caracterizado pela diferenciação do mesocarpo interno e endocarpo, e pelo amadurecimento das sementes. O endosperma é formado por células com paredes espessadas, grande quantidade de amido e cristais prismáticos de oxalato de cálcio. O embrião é basal espatulado rudimentar. No estádio final ocorre o amadurecimento do pericarpo...
Psychotria is the main Rubiaceae genus with nearly 1000 species worldwide. Owing to its magnitude, this genus is considered complex. Additionally, there is a lack of morphological features available to the definition of such group. The present study analyzed structural characteristics of seeds, leaves and pericarp of Psychotria hoffmannseggiana and Psychotria trichophora as well as the seedling of Psychotria hoffmannseggiana. The structure and development of the pericarp and seeds of such species are similar. The first fruit developmental stage consisted of the budding ovary and pre-anthesis flowers. The ovary is inferous, bicarpellary, bilocular with one ovule per loculus, and the placentation is basal axial. Seeds are originated from unitegmic anatropous ovule. During the second stage, there was a predominant meristematic activity both in the pericarp (mesocarp and endocarp) and in the seed tegmen. The third stage is characterized by the differentiation of the endocarp and inner mesocarp, and also the ripening of the seed. The endosperm is made up of thick wall cells, a large amount of starch and prismatic calcium oxalate crystals. The embryo is basal, spatulate and rudimentary. During the final stage the ripeness of the pericarp occurs by means of an increase in cell size and intercellular spaces of the mesocarp. The fruit increases in size and the mesocarp cells elongate considerably, exhibiting partially disintegrated walls. Mature fruits of both species are drupaceous with subglobose format. Such fruits have two free monospermatic pyrenes, dorsiventrally convex with a longitudinal sulcus on the ventral face. The leaves of Psychotria hoffmannseggiana and Psychotria trichophora are simple, opposite, elliptic, dorsiventral and hypostomatic. The petiole and blade epidermis is uniserial and pappilose concerning Psychotria hoffmannseggiana. Both species have paracitic... (Complete abstract click electronic access below)
Psychotria is the main Rubiaceae genus with nearly 1000 species worldwide. Owing to its magnitude, this genus is considered complex. Additionally, there is a lack of morphological features available to the definition of such group. The present study analyzed structural characteristics of seeds, leaves and pericarp of Psychotria hoffmannseggiana and Psychotria trichophora as well as the seedling of Psychotria hoffmannseggiana. The structure and development of the pericarp and seeds of such species are similar. The first fruit developmental stage consisted of the budding ovary and pre-anthesis flowers. The ovary is inferous, bicarpellary, bilocular with one ovule per loculus, and the placentation is basal axial. Seeds are originated from unitegmic anatropous ovule. During the second stage, there was a predominant meristematic activity both in the pericarp (mesocarp and endocarp) and in the seed tegmen. The third stage is characterized by the differentiation of the endocarp and inner mesocarp, and also the ripening of the seed. The endosperm is made up of thick wall cells, a large amount of starch and prismatic calcium oxalate crystals. The embryo is basal, spatulate and rudimentary. During the final stage the ripeness of the pericarp occurs by means of an increase in cell size and intercellular spaces of the mesocarp. The fruit increases in size and the mesocarp cells elongate considerably, exhibiting partially disintegrated walls. Mature fruits of both species are drupaceous with subglobose format. Such fruits have two free monospermatic pyrenes, dorsiventrally convex with a longitudinal sulcus on the ventral face. The leaves of Psychotria hoffmannseggiana and Psychotria trichophora are simple, opposite, elliptic, dorsiventral and hypostomatic. The petiole and blade epidermis is uniserial and pappilose concerning Psychotria hoffmannseggiana. Both species have paracitic... (Complete abstract click electronic access below)
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Anatomia vegetal, Fruto, Ontogênese, Anatomy of plants
Como citar
PIETROBOM, Rita de Cássia Violin. Morfoanatomia do pericarpo, semente, folha de Psychotria hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg. e Psychotria trichophora Müll. Arg., e desenvolvimento morfológico da plântula de Psychotria hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg. (Rubiaceae, Rubioideae, Psychotrieae). 2008. 91 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2008.