The germination behaviour of four Bromeliaceae species [Alcantarea imperialis (Carrière) Harms, Pitcairnia flammea Lindl., Vriesea heterostachys (Baker) L. B. Sm. and Vriesea penduliflora L. B. Sm.] from Ibitipoca State Park with contrasting habitat preferences, and representing two different plant growth forms were investigated. The aims of this study were: a) to characterize the seeds, providing information about germination type to describe the post-seminal development morphology; b) to evaluate percentage and rate of germination response to the effect of constant (from 10 °C to 40 °C) and fluctuating (20 °C-30 °C) temperatures; c) the ratio of red:far-red light (R:FR) and d) to different water potentials. The results showed that all species have very light seeds, ranging from 0.2 to 1.7 mg; the germination is epigeal with cryptocotylar seedlings. All species presented high germination under temperatures between 20 °C and 30 °C. Under darkness germination was successful only for Vriesea species, but seeds of all species required light for maximum germination. The R:FR value that resulted in 50% of maximum germination varied among species. Water stressed conditions reduced the percentage and rate of germination in all bromeliad species. A. imperialis and P. flammea were less sensitive to low water potentials. These contrasting germination requirements among the species studied were related to their habitat preferences.
red; rupestrian fields; seedling morphology; temperature; water potential
