Viable seeds of several native plant species present difficulties to germinate. Two trials were carried out to identify appropriate methodology to overcome seed dormancy in Operculina macrocarpa and Operculina alata. In the first one, the seeds of Operculata macrocarpa were submitted to the following treatments: dry cooling; wet heat; immersion in peroxide, immersion in hot water, immersion in sulfuric acid; wet cooling; mechanical scarification; soaking in potassium nitrate; and the control. Percentage of germination, hard seeds and dead seeds were determined. In the second trial, seeds of Operculina macrocarpa and Operculina alata were scarified and sown on paper and sand substrates and set to germinate under five different environmental conditions: continuous light and constant temperature (25ºC), continuous light and alternating temperatures (20ºC/16h-35ºC/8h), continuous darkness and constant temperature, continuous darkness with alternating temperatures (20ºC/16h-35ºC/8h), and alternating light and temperatures (light/35ºC/8h-darkness/20ºC/16h). Percentage and time to germination were determined. Mechanical scarification was the most efficient method to break dormancy in Operculina macrocarpa; towel paper, temperature between 20-30ºC and darkness were appropriate conditions for seed germination of Operculina macrocarpa and Operculina alata.
medicinal plant; dormancy; propagation
