Gas exchange and biomass production in young plants of Acapu (Voucapoua americana Aubl.) subjected to drought condition

Abstract

The experiment was conducted in a greenhouse at the Federal Rural University of Amazonia (UFRA) from November 2011 to July 2012. The plants were subjected to two water regimes: control (adequate irrigation) and water deficiency (water suspension) for 0, 10, 20 and 30 days period. The water potential in stressed plants was reduced after 30 days of drought. The photosynthetic rate, stomatal conductance and transpiration rate were reduced with increased water stress time in plant with more pronounced reductions in the 20 th and 30 th after induction of treatments. The concentration of ABA increased in leaves and roots of plants submitted to water deficit. Dry mass of shoot, root and total mass were decreased in plants under water stress. The suspension of irrigation for 10 days was sufficient to alter the metabolism of young Acapu plants. These results showed that young Acapu plants tolerate a water potential of up to -2.86 MPa, indicating that this species is not susceptible to water stress/suspension. This condition may favor the development and expansion of Voucapoua americana for the recovery of degraded areas in regions with limited available water.