Crecimiento y desarrollo en plantas juveniles de Apamate (Tabebuia rosea (Bertol.) A. DC.) sometidas a inundación

Abstract

This work describe the main morphological and physiological responses of apamate (Tabebuia rosea (Bertol.) A. DC.) juvenile plants to water stress by flooding. A two treatments randomized design was used. Six plants, per treatment were harvested every two weeks to evaluate root and shoot growth in diameter, length and biomass. Leaf nitrogen and chlorophyll content were determined. Daily courses of gas exchange, stomata conductance (Ks), transpiration rate (E), CO2 assimilation (A), and leaf water potential (PHf), were carried out under natural and saturating light. Plants adapted to flood conditions showing 100 % survival. Results on growth, gas exchange, stomata conductance, and morphological changes during flooding are probably adaptative strategies developed by T. rosea to withstand anoxic conditions. Photosynthetic rate decrease did not have significant effect on biomass increase in flooded seedlings. Even though chlorophyll and nitrogen content were higher in non-flooded plants, they did not show significant influence on CO2 assimilation rates. A slight PHf increase in flooded seedlings was observed, with little variation during the experimental period, indicating no significant water stress. Plants showed recovery signs by the end of the post-flooding period. Flooded plants showed higher rates that indicate that the elimination of the stress condition may have a triggering effect on photosynthesis, which resulted in a short term higher productivity. T. rosea is very tolerant species to soil flooding conditions.