Effect of manitol and NaCl on the germination of seeds of two leguminous species with importance to the Bahian dryland

Abstract

The present work studied the germinative response of seeds of Cenostigma gardnerianum Tul. and Anadenanthera colubrina (Vell.) Brenan, of the Family Fabaceae, under conditions of water and saline stress that are often present in the semi-arid region of Northeastern Brazil. The water stress obtained with manitol solution and the saline stress obtained with NaCl solution were tested by means of different osmotic potentials. The experiment was conducted in a box lined with paper filter and 50 seeds for each potential of each treatment. Material was kept in a germinating chamber at 25°C, in 10h of light alternating with 14h of darkness. Percent germination and average rate of germination were measured daily, beginning after ten days. The germination of the seeds diminished as the osmotic potential of the solutions of the two types of stresses diminished. The species demonstrated an acclimation to the drought conditions, because the decreases in osmotic potential typically had been limited between -0.2 to the -0.8 MPa.