New paper: Multiple fire-related cues stimulate germination in Chaenorhinum rubrifolium (Plantaginaceae), a rare annual in the Mediterranean Basin
Our paper on fire-related germination in a rare annual plant species in Turkey has been published in Seed Science Research: [Tavşanoğlu, Ç., Ergan, G., Çatav, Ş.S., Zare, G., Küçükakyüz, K., Özüdoğru, B. (2017) Multiple fire-related cues stimulate germination in Chaenorhinum rubrifolium (Plantaginaceae), a rare annual in the Mediterranean Basin. Seed Science Research. doi:10.1017/S0960258516000283]. In this paper, we examined the effect of several fire-related cues (including heat shocks, smoke, and chemicals found in smoke) on the germination of Chaenorhinum rubrifolium, a rare Mediterranean annual.
The species was only found in a restricted area in a recently burned site in Ören, Muğla, Turkey, and this is the first record of this species for Turkish flora. This record will be a subject of a separate taxonomic paper (Zare et al., submitted). Our findings on the germination behavior of the species in relation to fire also support this field observation.
Among the fire-related cues that were tested in the study, smoke solutions, nitrate, karrikinolide (a compound found in smoke), and mandelonitrile (an analogue of cyanohydrins that are found in smoke) stimulated germination, with an increase from zero percentage (in the control) up to ~47% (in karrikinolide treatment). Although various heat shocks did not stimulate germination, the combination of heat shock and smoke treatments increased germination up to 43% in comparison to smoke treatment only (~19%). The highest percentage of germination achieved in the combined treatment of karrikinolide and mandelonitrile (~63%). All these maximum values were reached under photoperiod conditions, and the germination was limited under dark conditions. These findings suggest that several fire-related cues operate to stimulate germination in C. rubrifolium.
Annual species are important components of post-fire plant communities of the Mediterranean Basin, but less studies have been conducted in relation to their fire-related germination in comparison to perennial species. Moreover, the Mediterranean Basin has been underestimated with respect to the presence of the species with fire-related germination in comparison with other Mediterranean-type ecosystems. Therefore, our study suggests that much evidence has been overlooked by focusing on the germination of perennial, especially woody, species.
Finally, our results on karrikinolide and mandelonitrile are the first records of the stimulation of germination by smoke chemicals in a plant species in the Mediterranean Basin, and constitute one of the novel aspects of our study.
Another blog entry (by J.G. Pausas) related to our paper can be reached from this link: http://jgpausas.blogs.uv.es/2017/01/21/a-new-pyroendemic-annual-plant/