OSMOTIC STRESS ON DESERT ROSE SEED GERMINATION

Abstract

The objective was to evaluate the germination behavior of Desert Rose seeds when subjected to different osmotic potentials (0.0; -0.2; -0.4; -0.6 and -0.8 Mpa) using KCl, Mannitol and polyethylene glycol-6000. The design was completely randomized in a 3 × 5 factorial scheme (3 agents × 5 osmotic potentials). Each treatment contained four replicates of 25 seeds, using blotting paper moistened with osmotic solutions inside gerbox boxes and placed in a BOD-type germinator at a temperature of 25 °C and a photoperiod of 12 hours, for 30 days. It was evaluated: percentage of germination, index of speed of germination and average time of germination. Data were submitted to analysis of variance by F test and means to polynomial regression analysis. The most negative osmotic potentials promote a significant reduction in all analyzed variables, and the limit of water tolerance for Desert Rose is between the potentials of -0.2 and -0.4 MPa.