Ecophysiology of Germination of Parkia platycephala Benth. Seeds

ABSTRACT Water is considered the most important environmental resource for the germination process. This study aimed to evaluate the germination performance of Parkia platycephala seeds under different conditions of water and saline stress. Seed germination was tested with solutions of poly (ethylene glycol) 6000 and sodium chloride (NaCl) at seven osmotic potentials [0.0, -0.2, -0.4, -0.6, -0.8, -1.0, and -1.2MPa (megapascal)] and four replicates with 25 seeds in a completely randomized design, simulating the water and saline stress levels, respectively. The following seedling variables were evaluated: germination percentage, germination speed index, length, and dry mass. Results showed significant interaction between the agent and the osmotic potential for all evaluated variables. P. platycephala seeds presented higher tolerance to saline stress simulated by NaCl than to water stress, showing germination performance appropriate for glycophyte plants.