Germinação de sementes de Dyckia tuberosa (Vell.) Beer (Bromeliaceae) sob diferentes temperaturas em luz e escuro

Abstract

The effects of temperature and light on the germination of seeds of Dyckia tuberosa (Vell.) Beer, a terrestrial bromeliad from "cerrado", were studied. Seeds collected at Estação Ecológica of Itirapina, São Paulo State, were incubated at constant temperatures in the range of 10 to 45°C, under continuous white light and darkness. The range of temperature with highest germinability under light was from 15 to 40°C and from 20 to 40°C in darkness, with no germination at 10 and 45°C for light and darkness. For both, light and darkness, the optimum temperature was in the range of 30 to 35°C. The high germinability at high temperatures shows that D. tuberosa is able to germinate in open areas and the light insensitivity of the seeds indicates that they can also germinate in conditions of completely darkness. Apparently, the germination process is not a limiting factor for this species.