Armazenamento de sementes e concentrações de ágar no cultivo in vitro de Brassavola tuberculata Hook. (Orchidaceae)

In vitro sowing and seed banks contributes to the conservation of the genetic variability of the orchids. Aimed to evaluate the storage time and agar concentrations on the in vitro germination of Brassavola tuberculata Hook. Seed samples were dried for 14 days and stored for 0, 30, 60 and 90 days under 4±2 oC. The culture medium was ½ MS, supplemented with agar (0; 1; 2; 3; 4; 5; 6; 7 or 8 g L-1). At 30 days after sowing the germination percentage was evaluated and the data were submitted for analysis of variance. The B. tuberculata seeds germinated at all concentrations of agar and storage periods evaluated, presenting average germination above 70%. Germination percentage decreases with increasing storage period and agar concentrations. Thus, for in vitro sowing of this species, seeds stored for up to 30 days are recommended, regardless of the agar concentration used in the culture medium.