Conteúdo e variação sazonal de carboidratos ocorrentes na flora da Mata Atlântica do Espírito Santo

• Autor(a) principal: Clippel, Joscineia Kelli
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/9951
• topic: Non-structural carbohydrates; Cell wall storage carbohydrates; Seasonal variation; Water deficit; Atlantic Forest flora; Carboidratos não estruturais; Polissacarídeos de reserva de parede celular; Variação sazonal; Défice hídrico; Agronomia; Carboidratos; Polissacarídeos; Plantas - Espírito Santo (Estado); Mata Atlântica; Espírito Santo (Estado); 57

In Plants, the main storage carbohydrates include starch, soluble sugar, fructans and cell wall polysaccarides. Moreover, carbohydrates act like energetic substrate and structural compounds, many of these sugars can act as a protection against environmental stress in growth periods. Carbohydrates are used in food, pharmaceutical, cosmetic and textile industries. Although they have wide economic and ecologic importance, relatively little is known about their yield in plants native to the Atlantic present, especially in Espírito Santo (ES). This study was performed on order to contribute to more information. Non-structural carbohydrates were analysed from underground organs of the herbaceous Dioscorea sp. 1 (Dioscoriaceae), Dioscorea sp. 2 (Dioscoriaceae), Hedychium coronarium J. Koening (Zingiberaceae), Hippeastrum reticulatum Herb. (Amaryllidaceae), Prescottia nivalis Barb. Rodr. (Orquidaceae), Scadoxus multiflorus Martyn (Amaryllidaceae) and Sinningia aghensis Chautems (Gesneriaceae). To evaluate the cell wall polysaccarides, seeds of the herb Canavalia rosea L. and of the tree species Cassia fistula L., Cassia grandis L., Erythrina variegata L., Hymenaea coubaril L. and Ormosia arborea (Vell.) Harms (Leguminosae) were used. The soluble carbohydrates seasonal variation was performed in S. aghensis tuberculum. On the whole, Dioscoriaceae tuberous plants are rich in starch, reaching 50% in Discorea sp. 1 dry mass (DM). The species that exhibited the greatest amounts of fructose were the bulbous H. reticulatum (25% DM) and S. multiflorus (8,5% DM) and the rhizomatous P. nivalis (6,7% MS). The biggest soluble sugar purports, especially sucrose (63% DM), also were seen in P. nivalis. The tuberous Dioscorea sp. 2 and S. aghensis and the rhizomatous Hedychium coronarium presented the lowest total sugar and starch values, which could present another carbohydrates order on the analysed season. The high fructose content in H. reticulatum suggests the presence of fructans. From the cell wall storage polysaccaride purport analysed, the greatest purports were found in Hymenea coubaril seeds (70% DM), followed by Cassia grandis (50% DM) and Canavalia rosea (40% DM). E. variegata and O. arborea exhibited the lowest values of these compounds, representing 10 and 3% of DM respectively. Thus, H. coubaril, C. grandis and C. rosea appear take potential species in polysaccaride production for technological purposes. In carbohydrates seasonal variation analyses of S. aghensis tuberculum, the starch were 5,5% in autumn and 77,7% in winter, as of period which was reported lowest precipitation (3,6 mm). The total sugar soluble purport, sucrose and fructose were higher in summer, decreasing 50% in winter. As to glucose, greatest concentrations were found in autumn, followed by a conspicuous decrease in summer. The high concentration of starch in winter suggests that it may be linked to drought tolerance mechanisms.