Priming in lettuce seeds

Abstract

One of the methods used to promote the rapid and uniform germination of vegetable seeds is the use of osmotic conditioning. The technique aims to regulate the osmotic potential of the solution, thus restricting the entry of water into the seeds without them germinating during the process. This work evaluated the germination of lettuce seeds of Grand Rapids, Everglades, and Verônica cultivars, submitted to osmotic conditioning. The seeds were immersed in polyethylene glycol solutions (PEG 6000) at potentials of 0.0; -0.6; -0.8, and -1.0 MPa, and remained in imbibition for 14, 24, and 48 h. After this period, the seeds were germinated on paper, moistened with water at 2.5 times their mass, and kept at 20ºC for seven days. The experimental design used was completely randomized, in a factorial scheme with three cultivars, four osmotic potentials, and three temperatures, with four replications of 25 seeds each. The germination percentage, the germination speed index, the mean speed of germination, and the mean germination time were evaluated. Data were subjected to analysis of residual normality by the Shapiro-Wilk test and the homogeneity of variances using the Bartlett test and submitted to analysis of variance. Data from osmotic potential and time of imbibition were submitted to polynomial regression. The treatment means were compared at 5% probability. Seeds of ‘Grand Rapids’ and ‘Everglades’ showed positive effects after osmoconditiong treatments.