Análises morfofisiológicas de plantas de pau-brasil (Caesalpinia echinata Lam.) cultivadas em pleno sol e em sombreamento natural

• Autor(a) principal: Gama, Vinícius Novo
• Data de Publicação: 2013
• 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/10/10004
• topic: Forest succession; Photosynthetic efficiency; Leaf anatomy; Pigments; Soluble carbohydrates; Oxidative stress; Anatomia foliar; Pigmentos; Carboidratos solúveis; Agronomia; Ecofisiologia vegetal; Sucessão ecológica; Plantas - Desenvolvimento; Fotossíntese; Plantas - Anatomia; Stress oxidativo; 57

Caesalpinia echinataLam. is a endangered tree of the Atlantic Florest. Published data has demonstrated that this specie threedifferent leaf morphological variants, and variant small leaflet considered a secondary classification plant forest succession, in contrast with the results of growth medium leaflet variant observed in the field. The central aim of this study was to characterize some morphological, biochemical and physiological leaf morphotype average C. echinata contrasting under conditions of irradiance. This work was conducted at the Reserva Natural da Valein the municipality of Sooretama, ES. We analyzed average leaflets of fully expanded leaves us third-fourth of young plants of Brazil wood in two different light conditions: full sun and natural shade. Plants in full sun showed greater efficiency in capturing light energy, followed by a photochemical better utilization and higher net carbon assimilation, which possibly resulted in a higher content of soluble carbohydrates. Because of the imbalance photosynthetic presumed to have been an excess plant photorespiratory activity in shading in an attempt to prevent the formation of free radicals by reducing compounds formed. The energy that should be being used in photochemical reactions and / or biochemical plants to shading was, for the most part, dissipated as heat or re-emitted as fluorescence translocated to the production of antioxidative defense compounds of secondary metabolism. Therefore, the high light condition provided greater growth of population exposed to full sun in relation to plants exposed to low light. The morphology and anatomic levels of photosynthetic pigments of plants exposed to the sun presented in this study also indicate a strong tolerance to this variant of intense light condition. The results presented in this paper show that the direct solar radiation is configured as a condition more suitable for the planting of shading variant mean leaf of Brazil wood. Given these differences in morphology and ecophysiological variants of the species C. echinata, a restructuring is necessary taxonomic species in possible sub-specific taxa, for thus reestablish anew classification of Brazil wood in forest succession, and thus provide support for proper planting and management of this plant in reforestation programs