EFFECT OF WATER POTENTIAL ON GERMINATION OF SEEDS OF STYLOSANTHES-GUIANENSIS (AUBL) SW

Effect of water potential on germination of seeds of Slylosanthes guianensis (Aubl.) Sw. To evaluate the water potential effect on germination of S. guianensis two experiments were performed.The first one used osmotic pre-treatment in the imbibition phase and after this period (14 h) the seeds were germinated on filter paper moistened with distilled water. In the second experiment, besides the imbibition phase, seeds were kept in a range of water potentials during all the process. The potentials ranged from 0 to -18 bars, with 3 bars increments, induced by mannitol or by polyethylene glycol. Each treatment was replicated 3 times with 100 seeds per replication. The seeds pre-treated during imbibition had high germination percentage, the highest being the ones in polhyetylene glycol. In the second experiment the polyethylene glycol solutions reduced dramatically the germination percentage in relation to mannitol. From -12 bars on germination ceased in the polyethylene glycol treatments, while in mannitol solution there was 52,67% of germination, in the same water potential.