Anatomia foliar como subsídio para taxonomia de espécies de Chamaecrista seção Absus subseção Baseophyllum (Leguminosae - Caesalpinioideae)

• Autor(a) principal: Coutinho, ítalo Antônio Cotta
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2556
• topic: Ontogenesis; Histoquímica; Anatomia ecológica; Subtribo Cassinae; Análise multivariada; Ontogenesis; Histochemistry; Ecological anatomy; Subtribe Cassinae; Multivariate analysis; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::MORFOLOGIA VEGETAL::ANATOMIA VEGETAL

This paper aims at studying Chamaecrista species included in the sect. Absus subsect. Baseophyllum providing information on the morphology and anatomy of the leaflet blades, petiole/rachis, and glands found on the petiole/rachis which may be used on the separation of the varieties of Chamaecrista cytisoides (section Absus subsection Baseophyllum) into species, as defined by the molecular studies. The presence of glucose in the exudates of the glands confirmed that the petiolar/rachis glands are in fact EFNs. The EFNs arise from the protodermis, ground meristem and procambium. Histochemical tests detected the presence of neutral, acid muco- polysaccharides, pectins, mucilages, total proteins, and phenolic compounds in the EFN which may be indications of the presence of these substances in the nectar. All eight species of Chamaecrista sect. Absus subsect. Baseophyllum displayed a single- layered epidermis. Actinodromous-camptodromous-brochidodromous venation type, collateral vascular bundles arranged in open arc, layers of fibres and a sheath of cells containing prismatic crystals surrounding the vascular bundles, enlarged tracheids at the vein endings, vascular tissue of petiole/rachis with a pith parenchyma, accessory bundles, extrafloral nectaries, colleters, and non-secretory trichomes were observed in all the species studied and considered as unifying characters for this subsection. Position and type of stomata on leaves, type of mesophyll, number of both palisade and spongy parenchyma layers, presence of hypodermis, position of mucilage idioblasts in the leaflets, and number of accessory bundles were used to make distinction among the species. Principal component analysis (PCA) based on morphological and anatomical characters showed the clear separation of the eight species included within sect. Absus subsect. Baseophyllum.