Effects of smoke and heat-shock on germination in eight perennial Reseda species (Resedaceae)

Abstract

Reseda is an understudied genus regarding germination ecology. We studied the germination response of eight perennial Reseda species to fire related cues by performing a germination experiment including two aqueous smoke treatments (at 1:5 and 1:20 concentrations), one heat shock (100°C for 5 min.) treatment, and two corresponding controls. Smoke slightly decreased germination percentage in R. aucheri ssp. rotundifolia and R. minoica, and the reduction in R. luteola was statistically significant (P < 0.01). In contrary, smoke promoted germination in R. coodei, R. globulosa, and R. orientalis slightly, and markedly in R. anatolica (from 3 to 11%; P = 0.055). Heat shock treatment did not affect the germination in three of four species tested, but significantly increased germination percentage in R. luteola in comparison to the control (P = 0.046). Consequently, there was no consistent germination response to smoke or heat shock in Reseda species studied. This study is the most comprehensive study tested fire-related germination of several Reseda species and provides the first germination results on seven Reseda species. Further studies that include more species and treatments would show a more completed figure for fire-related germination patterns in the genus Reseda.