Morfo-anatomia e ontogênese do fruto e da semente de Tipuana tipu (Benth.) O. Kuntze (Fabaceae: Faboideae)
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Data
2001-03-01
Autores
MARTINS, MARCO ANTONIO GARCIA [UNESP]
OLIVEIRA, DENISE MARIA TROMBERT [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Botânica de São Paulo
Resumo
Frutos e sementes de Tipuana tipu foram analisados morfo-anatomicamente, durante seu desenvolvimento, objetivando descrever sua estrutura, esclarecer a origem da ala pericárpica e verificar a ocorrência de poliembrionia, hipótese levantada a partir de dados de literatura. Para tanto, preparou-se o laminário segundo técnicas convencionais e foram observados morfologicamente os embriões das sementes obtidas de 100 frutos. O fruto de T. tipu é uma sâmara, cuja ala se desenvolve a partir da região látero-apical do ovário e lateral do estilete, já estando delineada no ovário de botões florais jovens. As sementes, provenientes de óvulos bitegumentados, são unitegumentadas e testais. A testa não exibe a estrutura característica do tegumento das leguminosas, como é freqüente em espécies de frutos indeiscentes. O hilo, contudo, apresenta a típica estrutura das Faboideae. São sementes exalbuminosas, contendo embrião com eixo e cotilédones bem diferenciados. Dos 100 frutos analisados morfologicamente, 61% eram monospérmicos, 34% dispérmicos e apenas 5% trispérmicos. do total de 144 sementes avaliadas, somente 2% eram poliembriônicas, com dois embriões por unidade.
Fruits and seeds of Tipuana tipu were morphologically and anatomically analyzed during development. The origin of the pericarpic wing was elucidated and the hypothesis of the occurrence of polyembriony mentioned in literature was verified. Slides were prepared according to the conventional techniques. The fruit of Tipuana tipu is a typical samara. Its wing originates from the lateral and terminal regions of the ovary and from the lateral of the style. The wing can be already traced in young ovaries of floral buds. Bitegmic ovules develop into testal seeds. The testa is not similar to those seen in typical legume integuments, frequently observed in species with indehiscent fruits. However, the hilum is typical of Faboideae. Seeds are exalbuminous and embryos present cotyledons and embryonic axis well developed. From 100 fruits analyzed mophologically, 61% were one-seeded, 34% two-seeded and only 5% three-seeded. From 144 seeds evaluated, only 2% were polyembryonic, showing two embryos per unit.
Fruits and seeds of Tipuana tipu were morphologically and anatomically analyzed during development. The origin of the pericarpic wing was elucidated and the hypothesis of the occurrence of polyembriony mentioned in literature was verified. Slides were prepared according to the conventional techniques. The fruit of Tipuana tipu is a typical samara. Its wing originates from the lateral and terminal regions of the ovary and from the lateral of the style. The wing can be already traced in young ovaries of floral buds. Bitegmic ovules develop into testal seeds. The testa is not similar to those seen in typical legume integuments, frequently observed in species with indehiscent fruits. However, the hilum is typical of Faboideae. Seeds are exalbuminous and embryos present cotyledons and embryonic axis well developed. From 100 fruits analyzed mophologically, 61% were one-seeded, 34% two-seeded and only 5% three-seeded. From 144 seeds evaluated, only 2% were polyembryonic, showing two embryos per unit.
Descrição
Palavras-chave
Tipuana tipu, Fabaceae, fruit, seed, development
Como citar
Brazilian Journal of Botany. Sociedade Botânica de São Paulo, v. 24, n. 1, p. 109-121, 2001.