Germination of Ormosia arborea (Vell.) Harms subjected to different periods of exposure and concentration of GA3 post mechanical scarification

Abstract

Several authors have verified the origins and the overcoming of dormancy in the seeds of Ormosia arborea, however, there are studies considering the exposition of the seeds to the gibberellic acid for 3 hours. This study aimed to evaluate the percentage, the average speed of germination and deterioration of the seeds of O. arborea. The seeds were subjected to mechanical scarification using scissors and presoaked in gibbrellic acid at concentrations of 5, 10 and 20 mg.L-1 for periods of 1, 3, 6 and 9 hours. Batches of 100 seeds were distributed in four petri dishes, remained in B.O.D. under constant temperature of 25 °C and light intensity of 116 μmol.m2.s-1. The seeds germinated were counted daily and
removed from the B.O.D. by root protrusion. The data about germination percentage, average speed of germination and deterioration were submitted to analysis of variance. It was found that the germination of O. arborea was significantly affected by the pre-soaking in GA3 and the exposure at 20 mg.L-1 for the period of 6 hours had a higher germination rate among the averages. It was observed an increase in the
speed of germination and decay rate of deterioration of the seeds by high concentrations of gibberellic acid, as well as the period of exposure to GA3.