Fire as a novel technique to stimulate adventitious shoots in the laboratory

Abstract

Fire-stimulated flowering and fire-stimulated resprouting are associated traits common in plants that evolved in fire-prone habitats, e.g., Vellozia pyrantha, an iconic plant that has economic potential and is endemic to a fully protected area. By combining a natural phenomenon that drives demography and in situ evolution, we tested if fire can be used as a novel technique for plant multiplication through vegetative bud activation in V. pyrantha. The basal parts of microplants cultivated for 60 days (5 to 6 cm tall) were exposed to a flame using a Bunsen burner for five periods controlled by a timer (2, 4, 6, 8, and 10 s) and compared to unburned plants (control). After 30 days, the number of new shoots was counted, and the length of the longest shoot produced per individual was measured. Adventitious shoot development started 7 days after the fire incidence. The number of shoots per individual and length of the longest shoot produced were significantly higher in the 6- to 10-s treatments. Fire was an efficient and cheap way to induce adventitious shoot formation. This new method could also be applied to other resprouter species from fire-prone environments in the world. By combining a natural phenomenon that drives evolution with the bud stimulus expected, we found fire as an efficient and cheap way to induce buds.