Hypericum perforatum L. and H. brasiliense Choisy, both belonging to the Clusiaceae family, are plant species of remarkable medicinal value. The former is commercially grown in Europe, and widely used as a phytotherapic for depression treatment while the latter, native to Brazil, has been recently studied as to its similar pharmacological potential. In this research work, seeds of both species were investigated as to the trait 1.000 seeds weight and the effects of several germination conditions (four temperature regimes: 20, 25, 30 and 20-30 ºC), presence or absence of light; presence or absence of 0.2% potassium nitrate in the seed germination medium. The results for 1.000 seeds weight were 0.13 g (7,692 seeds/g) and 0.02 g (50,000 seeds /g) for H. perforatum and H. brasiliense, respectively. The highest seed germination rate increases were observed with the following temperature regimes: 20 ºC or 20-30 ºC (H. perforatum) and 30 ºC (H. brasiliense). White light was required for seed germination in both species; moreover, light effect was more pronounced in H. brasiliense. In H. perforatum the light effect was strongly marked only at 20-30 ºC while in H. brasiliense it was present in all studied temperature regimes. Germination substrate moistening with potassium nitrate was effective for H. brasiliense but did not affect H. perforatum seed germination.
Hypericum perforatum; Hypericum brasiliense; medicinal plants; seeds; seed dry mass; germination percentage
