Morfologia, micromorfologia e anatomia de nectários extraflorais em espécies de Senna mill. e chamaecrista moench (leguminosae, cassinae)

• Autor(a) principal: Cunha, Alex de Lima
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6223
• topic: Caesalpinoideae; Cerrado; Estruturas secretoras; Néctar; Caesalpinoideae; Cerrado; Nectar; Secretory structures; BOTANICA::FISIOLOGIA VEGETAL

Morphology, Micromorphology and Extrafloral Nectaries Anatomy in species of Senna Mill. and Chamaecrista Moench (Leguminosae, Cassinae). Extrafloral Nectaries (EFN) are nectar-secreting structures present in vegetative organs of various plant families. The EFN were identified in 113 families of Angiosperms, wherein Leguminosae was described with the greatest number of species with extrafloral nebulous in the world. The extrafloral nectaries’ shape and arrangement in plant organs are some of the effective tools that contribute to the taxonomic delimitation of several families of Angiosperms, especially the Leguminosae. This study aimed to carry out the morpho-anatomical, micromorphological and histochemical analysis of the extrafloral nectaries in Senna and Chamaecrista species, belonging to the subtribe Cassinae (Leguminosae). The plant material was collected in the following parks: Parque Estadual da Serra Dourada, Parque Estadual da Serra dos Pireneus and Parque Nacional da Chapada dos Veadeiros in the state of Goiás. The leaf samples containing EFN were subjected to photonic microtechniques and electronic scanning. We studied 17 taxa containing structured and high EFN arranged mainly in the leaves, and classified into eight different forms, ranging from sessile to stipitate. It has been found that the EFN location and shape of the studied species are a useful tool in group taxonomy, especially the generic level, since in Senna the EFN are located, usually in the rachis, the foliolar inserts, presenting conical, digitiform, fusiform, globular and ovoid, whereas in the Chamaecrista EFN are usually petiole, pateliform, obovoid and caliciform. The EFN varieties of C. desvauxii were studied in their anatomical structures and exhibited some similarities in the anatomical and histochemical organization. However, some characteristics distinguish themselves and can be used in the taxonomy of species, such as the nectariferous parenchyma presence in the NEF edge of Chamaecrista desvauxii var. peronadenia, feature not observed in other varieties; subnectariferous parenchyma cells elongated anticlinally in varieties Chamaecrista desvauxii var. langisdorffii and Chamaecrista desvauxii var. peronadenia; besides the occurrence of nucleated sclereids associated with vascular tissues in Chamaecrista desvauxii var. molissima. This study contributes to new information on the EFN species because the literature did not present information on the secreted chemical nature as well as its structural organization, confirming that the present secretory structures are really EFN.