The aim of this research was to determine the maximum tolerance limit of water and salt stress on
seed germination of Pterogyne nitens Tul. The experiments were carried out with four simultaneous replicates of
50 seeds previously scarified with sulfuric acid for five minutes and the date were submited to variance analysis and
Tukey?s test. For evaluation of water stress were used manitol and PEG 6000 solutions being the maximal tolerance
limit from -2.4 and -2.6MPa (for the manitol) and -1.0 to -1.2MPa (for the PEG 6000). The seeds submited to
the manitol solutions and PEG 6000 presented a significant reduction of germination rate at -0.4MPa and of the
germination at -0.6 and -0.4MPa, respectively. The salt stress was simulated with CaCl2, KCl, and NaCl solutions.
For CaCl2 and KCl solutions the maximal tolerance limit is between -1.6 and -1.8MPa and for NaCl solutions
between -2.0 and -2.2MPa. Pterogyne nitens seeds germinate at low osmotic potential for PEG 6000 and
manitol solutions and presented tolerance to the salts solutions evaluated.