Anatomia floral e aspectos reprodutivos de espécies de Poales (Monocotiledôneas)
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2011-05-31
Autores
Oriani, Aline [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A anatomia floral de espécies de Poales incluídas em Rapateaceae, Juncaceae, Xyridaceae, Eriocaulaceae e Mayacaceae e a biologia reprodutiva de espécies de Abolboda (Xyridaceae) foram estudadas visando contribuir com a taxonomia do grupo e elucidar relações inter e intrafamiliares. Em Rapateaceae, tricomas secretores de mucilagem presentes na base de todas as peças florais; sépalas, pétalas, anteras e estilete recobertos por cera de ornamentação estriada; pétalas com células epidérmicas curtas, de paredes sinuosas na face abaxial; anteras tetrasporangiadas, com células epidérmicas contendo compostos fenólicos; endotécio com espessamento em espiral; ovário tricarpelar, com septos incompletos; óvulos anátropos e bitegumentados; e o mesmo padrão de vascularização floral caracterizam a família. Cephalostemon e Rapatea apresentam grande similaridade, corroborando análises filogenéticas que os apontam como grupos-irmãos. Stegolepis apresenta muitas características distintivas, refletindo maior diversidade do gênero. Juncaceae caracteriza-se por apresentar tépalas com epiderme abaxial formada por células alongadas, de paredes sinuosas, e margens formadas pelo prolongamento da epiderme; endotécio com espessamento em espiral; grãos de pólen em tétrade; epiderme externa do ovário com invaginações nas regiões dos feixes dorsais dos carpelos; e presença de ginóforo. Juncus distingue-se por apresentar estômatos na face abaxial das tépalas e vários óvulos com placentação parietal, enquanto Luzula diferencia-se pela presença de compostos fenólicos nas tépalas, intumescimento da base das tépalas e dos filetes, androceu diplostêmone e presença de obturador no ovário, além de apresentar três óvulos com placentação basal. Nas xyrídeas, apêndices nectaríferos do estilete estão presentes em Xyridaceae e Eriocaulaceae e são estruturas homólogas...
The floral anatomy of Rapateaceae, Juncaceae, Xyridaceae, Eriocaulaceae and Mayacaceae, and the reproductive biology of Xyridaceae species were investigated in order to contribute to the taxonomy and to the better understanding of inter and infrafamilial relationships. In Rapateaceae, mucilage-secreting trichomes between the floral parts; sepals, petals, anthers and style covered by an ornamented cuticle; short epidermal cells, with sinuous walls in the abaxial surface of the petals; tetrasporangiate anthers with phenolic idioblasts in the epidermis; endothecium with spiral thickenings; tricarpelar ovary, with incomplete septa; anatropous, bitegmic ovules; and the same floral vascularization pattern characterize the family. Cephalostemon and Rapatea show a great number of similarities, corroborating the phylogenetic analyses that identify these genera as closely related. Stegolepis shows several distinctive characters, probably related to the greater diversity found in the genera. Juncaceae is characterized by tepals with sinuous-walled cells in the abaxial surface and with margins composed only of epidermis; endothecium with spiral thickenings; pollen in tetrad; invaginations in the ovary epidermis facing the carpel dorsal bundles; and gynophore. Juncus is distinguished by the presence of stomata in the abaxial epidermis of the tepals, and several ovules with parietal placentation, while Luzula differs by the occurrence of phenolic compounds in the tepals; intumescence of the basal region of tepals and filaments; diplostemonous androecium; ovarian obturator; and three ovules with basal placentation. In the xyrid clade, the stylar appengades of Xyridaceae and Eriocaulaceae are homologous structures, supporting the phylogenetic proximity of these two families. Eriocaulaceae and Xyridaceae also share the presence of elongate epidermal cells with straight walls in the petals; epipetalous ... (Complete abstract click electronic access below)
The floral anatomy of Rapateaceae, Juncaceae, Xyridaceae, Eriocaulaceae and Mayacaceae, and the reproductive biology of Xyridaceae species were investigated in order to contribute to the taxonomy and to the better understanding of inter and infrafamilial relationships. In Rapateaceae, mucilage-secreting trichomes between the floral parts; sepals, petals, anthers and style covered by an ornamented cuticle; short epidermal cells, with sinuous walls in the abaxial surface of the petals; tetrasporangiate anthers with phenolic idioblasts in the epidermis; endothecium with spiral thickenings; tricarpelar ovary, with incomplete septa; anatropous, bitegmic ovules; and the same floral vascularization pattern characterize the family. Cephalostemon and Rapatea show a great number of similarities, corroborating the phylogenetic analyses that identify these genera as closely related. Stegolepis shows several distinctive characters, probably related to the greater diversity found in the genera. Juncaceae is characterized by tepals with sinuous-walled cells in the abaxial surface and with margins composed only of epidermis; endothecium with spiral thickenings; pollen in tetrad; invaginations in the ovary epidermis facing the carpel dorsal bundles; and gynophore. Juncus is distinguished by the presence of stomata in the abaxial epidermis of the tepals, and several ovules with parietal placentation, while Luzula differs by the occurrence of phenolic compounds in the tepals; intumescence of the basal region of tepals and filaments; diplostemonous androecium; ovarian obturator; and three ovules with basal placentation. In the xyrid clade, the stylar appengades of Xyridaceae and Eriocaulaceae are homologous structures, supporting the phylogenetic proximity of these two families. Eriocaulaceae and Xyridaceae also share the presence of elongate epidermal cells with straight walls in the petals; epipetalous ... (Complete abstract click electronic access below)
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Palavras-chave
Anatomia vegetal, Plantas - Reprodução, Biologia reprodutiva, Floral anatomy
Como citar
ORIANI, Aline. Anatomia floral e aspectos reprodutivos de espécies de Poales (Monocotiledôneas). 2011. 118 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2011.