Effect of priming on the germination ofPeltophorum dubium seeds under water stress

Peltophorum dubium seeds provided by Anhembi, SP were scarified in 98% H2SO4 for 15 min to overcome mechanical dormancy. Seeds were primed in solutions of 0.2% Captan at 10 °C and 27°C, PEG 6000 −1.0 MPa at 10°C and 27°C, 0.5 mol KNO3, 0.75 Mol KNO3, 1.0 Mol KNO3. Eight treatments including the primed seeds and nonprimed seeds, five replicates with 100 seeds for each treatment, were set to 15-cm-Petri dish with double filter paper moistened with testing solution PEG in refrigerator at 27°C. For the experiments of all the groups, osmotic potential were 0.0, −0.2, −0.4, −0.6, −0.8, −1.0, −1.2, and −1.4 MPa.P. dubium seeds were also set to water stress experiment in rolled paper with PEG solutions from 0.0 to −1.0 M Pa. Germination percentage decreased with the increase of PEG concentration. Control group had a better germination percentage than other groups. Germination hardly occurred in PEG −1.4 MPa.