Germination of Encholirium spectabile Mart.ex Schult.Schult.f.Seeds in Response to Temperature and Water Stress

摘要

A study was conducted to examine the effects of different temperatures and water stress on Encholirium spectabile seeds. We evaluated the germination percentage, speed and time of germination of small (4.01 mm), at temperatures of 15°C, 20°C, 25°C, 30°C, 35°C, 40°C and 45°C and a photoperiod of 12 hours of light. Seeds were subjected to osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2 and -1.4 MPa, induced by solutions of polyethylene glycol. The results indicated an excellent germination of medium and large seeds at the temperatures of 20°C, 25°C, 30°C and 35°C. The temperature of 35°C provided the best mean germination time of large seeds and a higher speed rate of medium and large seeds. E. spectabile seeds germinate in a wide range of water deficit of -0.2 to -1.2 MPa. Germination reduced at concentrations of -1.0 and -1.2 MPa. No germination occurred at -1.4 MPa. Larger seeds showed the higher germination potential than medium and small seeds at the temperatures of 25°C, 30°C and 35°C and in the range ofwater deficit of -0.2 to -1.2 Mpa.