Seed viability of tropical forest species in seed soil banks is not well known. This research aimed to evaluate the seed vigour and potential viability of S. multijuga and S. macranthera in direct sowing under nursery conditions and to test the efficiency of the tetrazolium test to determine quickly the seed viability of these species. The germination test, tetrazolium test and seedling emergence test can be used to evaluate seed viability of two species. The tetrazolium test (concentration 0,075%, and 30ºC) was also used to evaluate the potential viability at 6, 12 and 18 months from seeds in a soil bank. S. multijuga seeds presented 93,1%; 65,3%; 52,5% and 17,7% potential viability at sowing and after 6, 12 and 18 months, in the soil bank respectively, and S. macranthera presented 79,3%; 73,9%; 32,5% and 14,7% at sowing and after 6, 12 and 18 months in soil bank, respectively. The species studied had typical behavior of a persistent seed bank.
physiological quality; forest specie; tetrazolium test
