title: Genetic component of flammability variation in a Mediterranean shrub.
abstract: Recurrent fires impose a strong selection pressure in many ecosystems worldwide. In such ecosystems, plant flammability is of paramount importance because it enhances population persistence, particularly in non-resprouting species. Indeed, there is evidence of phenotypic divergence of flammability under different fire regimes. Our general hypothesis is that flammability-enhancing traits are adaptive; here, we test whether they have a genetic component. To test this hypothesis, we used the postfire obligate seeder Ulex parviflorus from sites historically exposed to different fire recurrence. We associated molecular variation in potentially adaptive loci detected with a genomic scan (using AFLP markers) with individual phenotypic variability in flammability across fire regimes. We found that at least 42% of the phenotypic variation in flammability was explained by the genetic divergence in a subset of AFLP loci. In spite of generalized gene flow, the genetic variability was structured by differences in fire recurrence. Our results provide the first field evidence supporting that traits enhancing plant flammability have a genetic component and thus can be responding to natural selection driven by fire. These results highlight the importance of flammability as an adaptive trait in fire-prone ecosystems.
authors.affiliation: CIDE-CSIC, Ctra. Náquera Km. 4.5, 46113, Montcada, Valencia, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Moreira
authors.forename: M C
authors.initials: MC
authors.lastname: Castellanos
authors.forename: J G
authors.initials: JG
authors.lastname: Pausas
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D054458:Amplified Fragment Length Polymorphism Analysis; D001426:Bacterial Proteins; D017753:Ecosystem; D005390:Fires; D051456:Gene Flow; D056426:Genetic Loci; D005838:Genotype; D008074:Lipoproteins; D016015:Logistic Models; D019083:Mediterranean Region; D008565:Membrane Proteins; D010641:Phenotype; D012641:Selection, Genetic; D039762:Ulex / Q000235:genetics* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; C089313:SpaI protein, Bacillus subtilis
keywords: AFLP genome scan; Ulex parviflorus; fire regime; obligate seeder; phenotype-loci associations; plant flammability