Óxido nítrico na germinação de sementes de baixo vigor de Dalbergia nigra

Abstract

Nitric oxide is a compound that participates in many plant physiological processes, among which works by stimulating the germination both under normal and under stress conditions. This study aimed to investigate the effectiveness of potassium nitrate (KNO3) and sodium nitroprusside (SNP), forming nitric oxide, on the germination of seeds of low vigor of Dalbergia nigra, to determine the best conditions for the conditioning of the seeds of the species in these solutions. The seeds were pre-soaked in water or in solutions of KNO3 or SNP at the following concentrations: 0.01, 0.1, 1 and 10 mmol L-1, for periods of six, 12, 24 and 48 hours. Then, tests were conducted in germination chamber at 25 °C for 12 days, calculating the percentage of germination of seeds by counting daily that issued radicle and germination speed index (GSI). In pre-soaked seeds in solutions of KNO3and SNP, the seed germination at concentrations of 0.1 and 1 mmol L-1was higher than the others, and also higher than the control, that had averaged 48% seed. It is concluded that the application of KNO3 and SNP increased seed germination and seed vigor of Dalbergia nigra seeds.