EFFECT OF WATER STRESS SIMULATED WITH NACL, MANNITOL AND PEG (6000) ON THE GERMINATION Erythrina falcata Benth SEEDS

Erythrina falcata Benth. (Fabaceae) species is used in agroforestry, restoration of riparian vegetation in flooded areas, and in the recovery of degraded ecosystems. This work aimed to evaluate the possible effects of water stresses on germination of Erythrina falcata seeds. The study was carried out in The Forestry Seeds Laboratory, Universidade Federal do Parana (UFPR), in Parana state, Brazil. The experimental units consisted in boxes gerbox (25 seeds on 2 filter papers) with 10 ml of osmotic solution. Gerbox was sealed with PVC plastic film and led to germinate in Mangelsdorf type chamber (under light continues at 25 +/- 2 degrees C). Six osmotic potentials (0.0; -0.2; -0.4; -0.6; -0.8; and -1.0 MPa) were induced with NaCl, manitol and polyethylene glycol (PEG 6000). The lowest tolerance limit to water stress was observed in PEG solutions. The germination limit was -0.2 to -0.4 MPa of PEG, whereas the osmotic potentials tested with NaCl and mannitol did not affect the germination process.