Efeito da espermina na qualidade fisiológica de sementes de alface

Abstract

The objective of this study was to investigate the performance of growth regulators: Gibberellic acid, spermine and abscisic acid on germination and early growth of seedlings of lettuce cv. Grand Rapids. For this, experiments were conducted in greenhouse and laboratory. The seeds were treated with test solutions of gibberellic acid at a concentration of 0.5mM, spermine at a concentration of 0.05mM and abscisic acid at a concentration of 0.04mM and assessed by the tests of germination, first count of germination, emergence, index speed of emergence, length of shoot and root, fresh and dry seedling mass, electrical conductivity and activity of - amylase. The spermine applied individually while increasing the activity of -amylase had little effect on the induction of germination of lettuce, which generally reduced the viability and vigor lettuce. However, when combined with gibberellic acid or abscisic induce the growth of shoots when this overcoming the inhibitory action of abscisic acid. The abscisic acid had positive effect on the reorganization of membranes mitigating the effects of two other regulators. Based on the results, we can infer that the growth regulators did not affect the viability of lettuce seeds cv. Grand Rapids, and that seeds treated with spermine showed worse performance, lower rate of emergence and speed of emergence, high values of the electrical conductivity and inhibition of root growth.