Adequação do teste tetrazólio para concentração, temperatura e tempo de embebição, e sua influência na qualidade fisiológica de sementes de grão-de-bico

Abstract

The aim of this study was to adjust the tetrazolium test for chickpea seeds. Three imbibition times and two concentrations of the tetrazolium solution were used in the completely randomized design, in a 3x2 factorial scheme, with four replications. Two seed lots (1-Janaúba and 2-Januária) were used. Germination of the Januária seeds was superior to that of Janaúba. Lot 2 presented values of dry mass and normal seedlings higher than those of lot 1. There were no statistical differences for dry mass and seed moisture of the two lots. In the tetrazolium test, there was no difference between batches regarding vigor classes. Seed imbibition at 41 °C /6 h resulted in a lower percentage of vigorous / viable seeds compared to 41 °C/4 h and 30 °C /18 h, indicating seed damage.Tetrazolium concentrations did not influence the vigor and viability classes of both lots. In lot 1, there was significant interaction for classes 2 and 4 and temperature /imbibition time. The temperature and the imbibition time of 41 ºC/6 h and 30 ºC/18 h presented lower and higher percentages in classes 2 and 4, espectively. In lot 2, there was significant interaction only for class 4. The temperature and imbibition time of 41 ºC/6 h presented a higher percentage of seeds in class 4. It was concluded that the tetrazolium test was efficient for determination of vigor and of seed viability; the concentration of 0.075% is indicated because it uses less amount of tetrazolium salt; the combination of 41 °C/6h is indicated because of the rapidity and positive influence on the percentage of viable and vigorous seeds (classes 1 and 2).