RICE SEEDLING PERFORMANCE TREATED WITH GIBBERELLIC ACID AT DIFFERENT TEMPERATURES

Abstract

This work aimed to evaluate the initial performance of seedlings originated from seeds of rice cultivars treated with gibberellic acid and exposed to different growth temperatures. The cultivars SCS - 112, BRS 7-TAIM, BR IRGA 410 and IRGA 417 were used, soaked in concentrations of gibberellic acid of 0; 150; 300; 450; 600 and 750 mg L-1 and taken into germinator under temperatures of 15; 20 and 25oC. The evaluations were performed in relation to shoot and root of rice seedlings at 3; 7 and 21 days after sowing. The cultivars showed different dry matter production of shoot and root as gibberellic acid concentration, temperature and time of evaluation. The better initial performance of seedlings exposed to gibberellic acid shows the higher expression of the rice seeds vigor and demonstrates the superiority in efficiency of different physiological processes involved in the resumption of growth the embryo. Thus, gibberellic acid favors the growth of the rice seedlings over time.