THE PHYSIOLOGICAL POTENTIAL OF MARANDU GRASS SEEDS UNDER WATER STRESS CONDITIONED WITH ASCORBIC ACID

Abstract

Water limitation is one of the main factors that influence the germination process, affecting crop establishment. Thus, alternatives capable of lessening such effects become of great relevance. The aim of this study was to evaluate the effect of ascorbic acid dosage on This study aimed of marandu grass seeds submitted to different water conditions. After establishing the immersion time for seed conditioning based on the soakingcurve, the experiment was conducted to evaluate the physiological potential, in a 3x5 factorial scheme, composed of three osmotic potentials (0; -0.2 and -0.4 MPa) and five ascorbic acid doses (0, 20, 40, 60 and 80 mM), with four repetitions. The germination, root protrusion, first germination count, germination speed index, root length and seedling shoots were evaluated. The physiological potential of the seeds was negatively affected by water stress induced by polyethylene glycol 6000, with deleterious effects on osmotic potentials -0.2 and -0.4 MPa. However, ascorbic acid conditioning at doses between 40 and 50 mM promoted improvements in seed germination performance and alleviated the harmful effects promoted by low water availability under the -0.2 MPa potential, stimulating tolerance to water stress. Improvements were also obtained in root and shoot growth of seedlings originated from seeds submitted to -0.4 MPa potential after conditioning.