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Web Ecology An open-access peer-reviewed journal
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Volume 18, issue 1 | Copyright
Web Ecol., 18, 7-13, 2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Standard article 29 Jan 2018

Standard article | 29 Jan 2018

Heat shock and plant leachates regulate seed germination of the endangered carnivorous plant Drosophyllum lusitanicum

Susana Gómez-González1,2, Maria Paniw1,3, Kamila Antunes4, and Fernando Ojeda1 Susana Gómez-González et al.
  • 1Departamento de Biología-IVAGRO, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, 11510, Spain
  • 2Centre for Science and Resilience Research (CR)2, Santiago, 8370361, Chile
  • 3Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, 8057, Switzerland
  • 4Departamento de Agronomia – DAG, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 39100-000 Diamantina, Brazil

Abstract. In fire-prone ecosystems, many plant species have specialized mechanisms of seed dormancy that ensure a successful recruitment after fire. A well-documented mechanism is the germination stimulated by fire-related cues, such as heat shock and smoke. However, less is known about the role of inhibitory germination signals (e.g. allelopathy) in regulating post-fire recruitment. Plant leachates derived from the unburned vegetation can enforce dormancy by means of allelopathic compounds, acting as a signal of unfavourable (highly competitive) niche for germination in pyrophyte species. Here, we assessed the separate effects of heat shock and plant leachates on seed germination of Drosophyllum lusitanicum, an endangered carnivorous plant endemic to Mediterranean fire-prone heathlands. We performed a germination experiment in which seeds were subjected to three treatments: (1) 5min at 100°C, (2) watering with plant leachate, and (3) control. Germination rate and seed viability was determined after 63 days. Heat shock stimulated seed germination in D. lusitanicum while plant leachates had inhibitory germination effects without reducing seed viability. Thus, both positive and negative signals could be involved in its successful post-fire recruitment. Fire would break seed dormancy and stimulate seed germination of D. lusitanicum through high temperatures, but also by eliminating allelochemical compounds from the soil. These results help to understand the population dynamics patterns found for D. lusitanicum in natural populations, and highlight the role of fire in the ecology and conservation of this endangered species. Seed dormancy imposed by plant-derived leachates as an adaptive mechanism should be considered more in fire ecology theory.

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