Tratamento pré-germinativo de sementes florestais com peróxido de hidrogênio

Abstract

The objective of this study was to investigate the physiological response of ipê-amarelo, candeia and lobeira seeds pre-soaked in solutions of hydrogen peroxide.. Ipê-amarelo seeds were soaked in solutions at concentrations 0, 10, 40 and 100 mM, for 24 and 48 hours. Candeia and lobeira seeds were soaked in solutions at concentrations of 0, 10, 20, 30, 40, 100 and 150 mM, for 5, 24 and 48 hours for candeia and for 48 hours for lobeira. Seeds of ipê-amarelo were embedded in 0, 10, 20, 30, 40 and 100 mM concentrations of hydrogen peroxide solutions for 48 hours for the study of germination under thermal stress and at concentrations of 0, 10, 40 and 100 mM for the study of germination in water stress. Candeia seeds were soaked in solutions at concentrations of 0, 10, 40 and 100 mM, for 5 hours. For the germination of ipê-amarelo seeds, temperatures of 15 ° C and 25 ° C were used and for candeia seeds the temperatures of 10 ° C and 35 ° C. Ipê-amarelo seeds, after pre-soaking in H2O2 solutions were placed to germinate in solutions of PEG in potentials of 0, -0.2 and -0.9 MPa. The treatments do not affect the germination of ipê-amarelo. However, smaller doses (10 mM) affect the speed (IVG) and uniformity of germination (U 75,25). The treatment improves candeia seed germination when the incubation time is 5 h at concentrations between 20 and 40 mM. Larger doses (100 and 150 mM) have a toxic effect. Under thermal stress conditions, the treatment does not affect germination, but improves uniformity at the dose of 40 mM. The treatment with hydrogen peroxide does not interfere in the germination of candeia seeds in thermal stress, but increases the uniformity in the concentration of 40 mM.