The physiological quality of lettuce (Lactuca sativa L.) seeds can be evaluated by germination and vigor tests. However only the germination test is considered as standardized for this species. The objectives of the study were to compare and to identify reliable tests to evaluate the physiological potential of lettuce seeds. Seed lots of cv. Regina and Vera were evalueted by standard germination, first count, osmotic solution, accelerated aging, seedling emergence, electrical conductivity, seedling length and dry mass tests. The experimental design was completely randomized, with mean comparisons by the Tuckey test (p < 0,05). Results of the germination test showed differences among seed lots of 'Regina' and the vigor tests ranked the seed lots according to the physiological potential. However it was observed for 'Vera' that the vigor tests did not detect significant differences among the lots, except for the accelerated aging test. It was concluded that the most suitable tests for determination of the physiological potential of lettuce seeds are the germination first count, accelerated aging and seedling emergence, while the osmotic solution and electrical conductivity tests still need additional studies to adapt their procedures and to make possible the consistent use for lettuce seeds.
Lactuca sativa; germination; vigor tests
