Imbibition profile in polyethylene glycol 6000 osmotic solution and physiological potential of soybean seeds

Abstract

The objective of this work was to study the imbibition profile in water or in polyethylene glycol 6000 osmotic solution and the effect of the osmoconditioning on the germination and vigor of seeds of six soybean cultivars - Confiança, UFV-16, Splendor, Garantia, UFVS 2005 and UFV-18. The cultivars were grown in the field at Viçosa, Minas Gerais, in a randomized complete block design, the seeds were harvested at the R8 stage and 15 and 30 days later. Seed samples of each cultivar per harvest time and replication were soaked in distilled water (control) or osmoconditioned in -0.8 MPa PEG 6000 solution at 20 °C, for 96 h, in the presence of 0.2% Captan fungicide. Vigor and viability of the seeds were evaluated by the first and final counting in the germination test on paper rolls and speed of seedling emergence on sand seedbed. The imbibition speed and the humidity of the osmoconditioned seeds of all six cultivars and three harvest times were lower than of those seeds soaked in water. The germination and vigor of osmoconditioned seeds were higher for all cultivars at all harvest times, mainly with 30 days harvest delay, indicating the conditioning efficacy to increase the germination of weathered seeds.