Electrical conductivity and osmotic conditioning with polyethylene glycol in storage Caryocar brasiliense seeds

Abstract

The propagation of Caryocar brasiliense (pequizeiro) is still little known. This study aimed to evaluate different osmotic conditions with polyethylene glycol (PEG) in the imbibition process and in the germination of pequi seeds, in addition to verifying the electrical conductivity to evaluate the viability of these seeds. The experiment was conducted with freshly dispersed pyrenes and with pyrenes stored for 90 days. The electrical conductivity of the aqueous solution was measured every six hours for up to 48 hours, using five replications with 20 seeds. The extracted seeds were placed in PEG solutions with osmotic potentials: 0.0; −1.0; −2.0; −3.0; −4.0 MPa, monitored at intervals of 12 hours to 60 hours, plus additional treatment with dry seeds without any type of imbibition. The design was completely randomized with four replications of 25 seeds for germination and four replications of ten seeds for monitoring water content during imbibition. Germination percentage, germination speed index (GSI), percentage of dead and live seeds at 40 days were evaluated. In seeds with longer storage time, the electrical conductivity was higher. Treatments that were not submitted to PEG showed higher GSI, lower mortality percentage and higher germination percentage with 40% and 37%, respectively. The electrical conductivity test was adequate.