Viabilidade de sementes Senegalia polyphylla (DC.) Britton e Rose pelo teste do tetrazólio.

Abstract

T he use of tetrazolium test on forest species is still incipient and presents some positive results. The aim of this study was to determine the viability of seeds of Senegalia polyphylla by tetrazolium test. It was tested two soaking times: 36 and 42 hours, two immersion times: 3 and 6 hours, and three tetrazolium salt solutions concentrations: 0.075, 0.1 e 0.5%, maintained at 30 ºC constant temperature, totaling 12 treatments with 4 replicates of 25 seeds each. It was evaluated viable and vigorous seeds, viable and non-vigorous seeds and unviable seeds percentages. The statistical design was completely randomized in factorial 3 x 2 x 2 (salt concentration x soaking time x immersion in salt solution time). The variance analysis and the treatments’ average comparison were performed by Tukey test at 5% probability. The results showed that the immersion time was the only factor that influenced the viability assessment of Senegalia polyphylla seeds. The colored seeds evaluation was difficult at 0.5% concentration of chloride 2, 3, 5 triphenyltetrazolium. This study showed that the 6-hour immersion time was the best to assess seed viability. It is suggested 0.075% concentration and 36 hours soaking time because they are respectively more economical and faster for test conduction. The hypothesis that the tetrazolium test is efficient for evaluating Senegalia polyphylla seed viability was confirmed when compared to standard germination test.