Abstract

Queen of the night (Epiphyllum oxypetalum), an ornamental cactus, is widespread in many countries. The demand for this species is increasing because esthetic quality of its flowers is appreciated. This study aimed to analyze the influence of temperature, substrate and luminosity on the germination of E. oxypetalum seeds. A completely randomized design with four replications was used in a 3 x 2 x 2 factorial scheme, corresponding to three temperatures (20, 25 and 30°C), two substrates (blotting paper and sand of average particle size) and two luminosity conditions (light and dark). The percentage germination, germination speed index (GSI) and mean germination time (MGT) were evaluated. The 20°C treatment combined with the sand substrate and the presence of light provided favorable conditions for the germination of the seeds of E. oxypetalum, yielding a higher GSI and a shorter MGT; however, the species may be considered as preferentially photoblastic because of its ability to germinate in darkness.

Key words: Cactaceae, luminosity, ornamental plant, substrate, temperature, vigor.