Piptadenia stipulacea (Benth.) Ducke Seed Germination in Response to Temperature, Light and Water Stress

Abstract

The current study aimed to investigate the effects of the temperature, light, and water stress on Piptadenia stipulacea seed germination. It assessed germination percentage, speed and average germination time, root and stem length as well as the dry weight of seedlings subjected to the constant temperatures of 20°C, 25°C and 30°C and alternating temperatures from 20°C to 30°C. A 12-hour photoperiod was established in addition to the following light conditions: white, darkness, red and far red. The experimental design was completely randomized and four replicates of 25 seeds were performed for each treatment. Regarding water stress, seeds were subjected to osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8, -1.0, and -1.2 MPa, at 30°C and 12 h light/12 h darkness photoperiods. After they were mixed, 100 seeds were randomly selected for biometric measurement and they were found to be uneven with respect to size and weight. P. stipulacea seeds germinated under all tested temperature and light conditions. Germination under water stress occurred up to -0.8 MPa. The conclusion is that there was no germination from -1.0 MPa. The seeds are light-indifferent and germinate at the constant temperatures of 20°C, 25°C and 30°C and alternating temperatures from 20°C to 30°C.