Ecofisiologia, crescimento e bioquímica de Clusia grandiflora Splitg. (Clusiaceae), submetidas ao alagamento.

Abstract

Flooding soil promotes one of the most frequent abiotic stresses to which they are subjected some plants, and that can interfere with quality of ecosystems such as the Amazon forest that survives from their own organic material, and its delicate balance is extremely sensitive to any interference. Clusia grandiflora Splitz. is an erect perennial pioneer tree species, occurring mainly in the Amazon biome sandbank. The aim of this study was to determine some of the ecophysiological and biochemical mechanisms of stress tolerance by water flooding the ground. The experiment was conducted in a greenhouse at the Federal Rural University of Amazonia (UFRA) located in Belem-Para, from January to July 2014, when seedlings were used in Clusia grandiflora Splitz. The experimental design was completely randomized layout with 2 x 5 x 5: two water conditions - control "C" and the root flooding "A" x five evaluation periods - 0, 7, 14, 21 and 28 days x 5 reps and control flooded, totaling 50 units. The flooded plants were surrounded by a higher volume vessel, maintained with a water depth of 5 cm from the collect. Data were submitted to analysis of variance (ANOVA), the averages compared by Tukey test at level of 5%, the graphics produced by Sigma Plot 12.5 program. The water potential of the predawn (ψam), the foliar xylem water potential (ψx), relative water content (CRA), hydraulic conductivity (KL), and pressure Deficit vapor (DPVf-a) air sheet was reduced as increasing the stress time in the plants, photosynthesis (A), stomatal conductance (GS), transpiration (E) and stomatal resistance (Rs) showed a decrease in stressed plants, with reductions more pronounced in the 21st and 28th day. There was a significant decrease in growth height (HC), sheet number (NR), root length (CR), leaf area (AF) in flooding, not significant decrease in diameter of stalks, moreover, a significant increase length of adventitious roots (CR), diameter of adventitious roots (DRÎ) and formation of hypertrophic lenticels (ALH) in flooded plants. Dried pasta root (MSR), stem (MSC), leaves (MSF) and total (MST) decreased in flooded plants. Flooding induced increase in ammonium concentration (CAL), sucrose (SA), proline (Pro) and glycine betaine (GB) and in total soluble amino acid levels (AST), soluble carbohydrates (CST), both in leaves, as in the roots on the other hand caused a reduction in nitrate (CN), glutamine synthetase (GS), the starch concetrações (CA), and total soluble proteins (PST) in the leaves and roots. The flooded plants had direct and indirect significant correlation between physiological and biochemical variables, and biochemical variables between each other. Growth indicators, biomass, physiological and biochemical observed were efficient to evaluate the overall condition and metabolism of plants. The accumulation of AST, PRO, GB, LDH, ADH, AS and CST in leaf and root, and root translocation of the AC-to-sheet resulting from flooding intensity contributed to the adjustment of Metabolic plant, however, were unable to prevent the reduction in dry matter production. All plants survived the experiment, however, the stressed probably lack of oxygen supplied the roots of the formation of adventitious roots, hypertrophic lenticels, and stem cracking. C Gradiflora it showed promising for use as a pioneer plant in the reforestation of degraded areas.