A reversible smoke-induced secondary dormancy in Venus Flytrap (Dionaea muscipula) seed

Abstract

The Venus Flytrap (VFT) is fire adapted because it regenerates vegetatively from its rhizome after seasonal fires. Many fire-adapted plants have seed that germinate following smoke exposure. Mature VFT seed are quiescent and germinate almost immediately when exposed to appropriate physical environmental factors. Here we show that smoke exposure induces secondary dormancy in VFT seed. Smoke-exposed seed exhibit either complete inhibition or significant delays of germination; however, the secondary dormancy can be reversed by soaking the seed in hydrogen peroxide solution or stratifying the seed. Whereas the treatment with peroxide resulted in germination comparable to controls, stratification resulted in germination over a prolonged time period. We propose induced dormancy demonstrates a unique fire adaptation as dormancy would prevent summer germination under adverse conditions following fire and stagger germination later in the fall or spring following winter stratification, allowing germination over a wider and more favorable range of environmental conditions.