PHYSIOLOGICAL-RESPONSES OF VARIOUS SOYBEAN GENOTYPES TO WATER-STRESS

The analysis of drought resistance in five soybean cultivars (Glycine max (L.) Merr.) showed the occurrence of a wide genetic variability. The genotypes exhibited differences in their ability to save water in the absence of a water stress, to maintain high leaf water potentials or to tolerate low leaf water potentials during a water stress. The varietal behaviors are usually dependent on stomatal control, which rules photosynthetic processes. The differences observed concern the stomatal resistance of the adaxial side on the leaf in the absence of water stress and the stomatal closures on both sides on the leaf during water stress. There is good agreement between the physiological data obtained here and the agronomic characteristics already known.