Morfoanatomia dos órgãos reprodutivos e da plântula de Epiphyllum phyllanthus (L.) Haw. (Cactaceae)
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Data
2009-02-19
Autores
Almeida, Odair José Garcia de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Cactaceae distribui-se pelo continente americano, do sul e oeste do Canadá até o sul da Patagônia na Argentina e Chile. A família está inserida em Caryophyllales e possui cerca de 1.500 espécies. Epiphyllum phyllanthus (L.) Haw. é epífita obrigatória muito difundida na América do Sul, sendo a única espécie brasileira nativa de Epiphyllum Haw. A biologia reprodutiva em Cactaceae foi estudada em menos de 10% das espécies que a constituem e, esta limitada quantidade de dados, impede melhor entendimento dos mecanismos reprodutivos na família. Objetivou-se a realização de estudo morfológico e anatômico dos órgãos reprodutivos e da plântula de E. phyllanthus, através de: (i) análise morfoanatômica da flor; (ii) morfoanatomia e ontogenia do pericarpo e da semente e (iii) morfoanatomia da plântula. A flor é séssil, epígina com hipanto desenvolvido. Todos os verticilos florais apresentam epiderme unisseriada, glabra e estomatífera. O gineceu é sincárpico, com 9-10 carpelos, pluriovulado, de placentação parietal. O ovário possui feixes vasculares invertidos. A flor apresenta região nectarífera na face interna do hipanto. O óvulo é circinótropo, bitegumentado, crassinucelado, de funículo longo. O hipanto é de natureza receptacular. O fruto é do tipo cactídio de coloração róseo-roxo brilhante, superfície lisa e acumula concentração elevada de amido no pericarpo e na polpa, quando maduro. As sementes são campilótropas, pretas e de formato ovóide. A superfície externa ventral exibe relevo diferenciado, a região hilo-micropilar, de coloração esbranquiçada, onde ocorre arilo. O embrião é curvo com reserva lipoprotéica. Perisperma e endosperma persistem na semente madura, sem substâncias de reserva. A plântula é fanerocotiledonar e apresenta germinação epígea. Durante a germinação há hidratação e expansão de mucilagem na semente...
The Cactaceae family is widely distributed in the American continents, from the south and west of Canada to the south of Patagonia (Argentina and Chile). It is included in Caryophyllales and has approximately 1,500 species. Epiphyllum phyllanthus (L.) Haw. exhibits an obligatory epiphytic habit and is widespread in South America. Additionally, it is the only Epiphyllum Haw. species that is indigenous to Brazil. Studies concerning the reproductive biology of Cactaceae have been conducted in no more than 10 percent of the taxa, and such a limited amount of data precludes the suitable comprehension of the reproductive mechanisms in the family. The present work was aimed at providing a morphoanatomical description of the reproductive organs and seedlings of Epiphyllum phyllanthus by means of (i) flower morphoanatomical analysis; (ii) morphoanatomical and ontogenic studies of the pericarp and seed, and (iii) morphoanatomical analysis of seedling in developing. It was observed that the sessile and epigynous flower exhibit a well-developed hypanthium. All the flower whorls has uniseriate epidermis. The syncarpous and pluriovulate gynoecium exhibit 9-10 carpels and parietal placentation. The ovary has inverted bundles and the flower showed the nectariferous region on the inner surface of the hypanthium. The ovule is circinotropous, bitegmic, crassinucelate, and has a long funiculus. The hypanthium exhibit receptacular origin. The bright pinkish-purplish “cactidio-type” fruit has a smooth surface and, when it is ripe, exhibits a high concentration of starch in the pericarp and pulp. The seed is campylotropous, black and ovoid. Its ventral outer surface presents a differentiated relief that is the whitish hilum-micropylar region, in which the aril occurs. The curved embryo contains lipoprotein reserves. Perisperm and endosperm persist in the mature seed without reserve substances... (Complete abstract click electronic access below)
The Cactaceae family is widely distributed in the American continents, from the south and west of Canada to the south of Patagonia (Argentina and Chile). It is included in Caryophyllales and has approximately 1,500 species. Epiphyllum phyllanthus (L.) Haw. exhibits an obligatory epiphytic habit and is widespread in South America. Additionally, it is the only Epiphyllum Haw. species that is indigenous to Brazil. Studies concerning the reproductive biology of Cactaceae have been conducted in no more than 10 percent of the taxa, and such a limited amount of data precludes the suitable comprehension of the reproductive mechanisms in the family. The present work was aimed at providing a morphoanatomical description of the reproductive organs and seedlings of Epiphyllum phyllanthus by means of (i) flower morphoanatomical analysis; (ii) morphoanatomical and ontogenic studies of the pericarp and seed, and (iii) morphoanatomical analysis of seedling in developing. It was observed that the sessile and epigynous flower exhibit a well-developed hypanthium. All the flower whorls has uniseriate epidermis. The syncarpous and pluriovulate gynoecium exhibit 9-10 carpels and parietal placentation. The ovary has inverted bundles and the flower showed the nectariferous region on the inner surface of the hypanthium. The ovule is circinotropous, bitegmic, crassinucelate, and has a long funiculus. The hypanthium exhibit receptacular origin. The bright pinkish-purplish “cactidio-type” fruit has a smooth surface and, when it is ripe, exhibits a high concentration of starch in the pericarp and pulp. The seed is campylotropous, black and ovoid. Its ventral outer surface presents a differentiated relief that is the whitish hilum-micropylar region, in which the aril occurs. The curved embryo contains lipoprotein reserves. Perisperm and endosperm persist in the mature seed without reserve substances... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Anatomia vegetal, Epifitas, Embrião, Sementes, Mucilagem, Flores, Nectarios, Região hilo-micropolar, Fruto, Hipanto, Arilo, Estrutura de transição, Fruit, Aril, Epiphytic, Flower, Hilum-micropylar region, Hypanthium, Mucilage, Nectary, Seed, Transition structure
Como citar
ALMEIDA, Odair José Garcia de. Morfoanatomia dos órgãos reprodutivos e da plântula de Epiphyllum phyllanthus (L.) Haw. (Cactaceae). 2009. 100 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2009.