The epiphytic cactaceae Hylocereus setaceus (Salm-Dick ex DC.) Ralf Bauer seed germination is controlled by light and temperature

The effect of light and temperature on seed germination in Hylocereus setaceus was analyzed by isothermic incubations under continuous white light and darkness. The minimum temperature for germination was between 5 to 10 degrees C and the maximum between 45 to 50 degrees C. The optimum temperature was between 25 and 30 degrees C. The involvement of phytochrome, by very low fluence response, in controlled seed germination was attained by incubation in a gradient of photoequilibrium of phytochrome. The results indicated that seeds of H. setaceus germinated in a wide range of temperature, under canopy and in open areas, but in complete darkness they did not germinate.