© 1996 Heron Publishing—Victoria, Canada
Comparison of light-regulated seed germination in Ficus spp. and Cecropia obtusifolia: ecological implications
Carlos Vázquez-Yanes, Mariana Rojas-Aréchiga, Maria Esther Sánchez-Coronado and Alma Orozco-Segovia
Centro de Ecología UNAM, Apartado postal 70-275, Ciudad Universitaria, 04510 México, D.F., México / Received December 12, 1995
Summary
The major components of annual seed deposition in the rain forest at Los Tuxtlas, Veracruz, México are seeds of the pioneer
tree species Cecropia obtusifolia and those of some species of Ficus. Cecropia obtusifolia Bertol. forms a relatively persistent viable soil seed bank, whereas seeds of Ficus are seldom found in the soil. Both genera require light for seed germination; however, the species differ in their germination
responses to far red (FR) light under laboratory and field conditions. Seeds of C. obtusifolia did not germinate in low red/far red (R/FR) or pure FR, whereas seeds of the Ficus species did. This suggests that Ficus seeds do not become dormant under the light conditions (low R/FR ratio) beneath the leaf canopy of the rain forest. This
difference may explain why the species differ in their presence in the soil seed bank.
Keywords:
photoblastism, phytochrome, rain forest, seed dormancy, soil seed bank.
