Biologia dos coléteres foliares em Rubiaceae de cerrado e floresta estacional semidecídua do estado de São Paulo

• Autor(a) principal: Tresmondi, Fernanda [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/142985
• topic: Rubiácea; Secreção; Ultraestrutura (Biologia); Coléteres; Plantas dos cerrados; Rubiaceae

Colleters are responsible for the secretion of mucilaginous or resinous substance, usually associated with the protection of the meristem and developing organs against desiccation and damage by pathogens, herbivores, and also with the formation of bacterial leaf nodes. Additional compounds such as alkaloids, lipids and phenolic compounds may be present in the secretion of colleters. Variations in the composition to indicate the specificity and subcellular mechanisms for synthesis and release of colleters secretion of different species. In Rubiaceae colleters can be classified as: standard, reduced standard, intermediate, brush-like, winged, filiform, dendroid and lacrimiforme. This study compared 17 species of Rubiaceae occurring in savanna and semi-deciduous forest. Were evaluated morphology, distribution and histochemistry of stipular colleters using optical and scanning electron microscopy. To evaluate the subcellular mechanisms of the secretory cells of colleters eight species were selected with standard colleters with variation in the nature of secretion, which were subjected to analysis in a transmission electron microscope using conventional and cytochemical techniques - ZIO for marking endomembrane systems, osmium-imidazole for unsaturated lipids and polysaccharides to Thiéry. Moreover, in situ monitoring was performed microclimate, budding period and proportion of new leaves damaged apices on both ecosystems throughout a year. Among the 17 species studied, 14 showed colleters standard with variation in the distribution and size. The secretion varied from predominantly hydrophilic, mixed to predominantly lipophilic. This secretion variation reflected in differences in the populations of organelles between species, mainly on the number and appearance of plastids, endoplasmic reticulum and dictyosomes including vesicles associated with these. Secretion accumulation sites were evident in the outer periclinal wall of epithelial ...