The aim of this study was to investigate the germination of seeds of Miconia albicans, M. langosdorffii, M. rubiginosa, M. stenostachya, Schizocetron elegans and Tibouchina gracilis that occur in Cerrado areas. The seeds were exposed daily to light during 0, 10 min, 15 min, 30 min, 60 min, 90 min, 180 min, 360 min, 720 min and 1.440 min at 25 ºC. Five gradients of phytochrome photoequilibrium (j) were tested in seeds of M. albicans and M. rubiginosa. The effect of temperature was observed at constant 15, 20, 25, 30 and 35 ºC, and alternated temperatures of 30/20 ºC, under continuous light and darkness. Germinability and speed of germination were analyzed. Seeds of all the species are photoblastic. Seeds of M. albicans, M. langsdorffii, S. elegans and T. gracilis need at least 60 to 90 min of light to start germination. M. stenostachya (15 min) and M. rubiginosa (360 min) showed the extreme responses to light treatment. The germinability of the seeds of M. albicans increased under higher gradients of R:FR photoequilibrium. Germination was low inM. rubiginosa, so the response of the seeds to R:FR photoequilibrium was inconclusive. In relation to temperature, germination occurred mainly between constant 20 ºC and 30 ºC and at 30/20 ºC. Germination under light and with temperatures between 20 ºC and 30 ºC are characteristics that may contribute to the establishment of plantlets of the Melastomataceae in the cerrado. The seeds remain in the soil seed bank and may germinate when light is available even for short periods and despite the daily variation in temperature.
light; Melastomataceae; seed germination; temperature
