Viabilidade e vigor de sementes de Moringa oleifera Lam. pelo teste de tetrazólio

Abstract

The study aimed to establish an effective procedure for testing tetrazolium in evaluating the viability and vigor of Moringa oleifera seeds, a plant with diverse applications, from medicinal to water treatment. The tetrazolium test was chosen because of its speed and ability to provide a detailed analysis of seed condition. The seeds were pre-conditioned for five hours at 25°C, between paper towels, to facilitate absorption of the tetrazolium solution. Only the cotyledons with embryos were used and immersed in tetrazolium solution at different concentrations (0.05%, 0.075% and 0.1%) for variable periods (1, 2 and 3 hours) at 30°C, in a dark chamber. Seeds were considered viable if the embryo was pink in color, and non-viable if discolored, yellow or intense red. The test was applied to both seeds harvested in 2020 and seeds recently harvested in 2021. Viability assessment was carried out using the DIC. The results showed a high germination rate (100%) and there was no statistical difference between the control and the percentage of viable seeds after staining periods of 2 and 3 hours, at concentrations of 0.075% and 0.05%, respectively. The viability rate ranged from 95% to 97% for seeds harvested in 2020 and from 99% to 100% for seeds harvested in 2021, depending on the harvest month. It was concluded that the most appropriate procedure for testing tetrazolium in M. oleifera seeds is immersion in a 0.05% solution for 3 hours, providing an accurate assessment of seed viability and vigor. This standardized method can be useful to guarantee the quality of M. oleifera seeds, essential for its wide range of applications, from its medicinal use to its contribution to water purification in tropical and semi-arid regions.