Publicación Artículo científico (article).

Weak genetic differentiation but strong climate-induced selective pressure toward the rear edge of mountain pine in north-eastern Spain

Digital.CSIC. Repositorio Institucional del CSIC
oai:digital.csic.es:10261/345131
Digital.CSIC. Repositorio Institucional del CSIC
  • Méndez-Cea, Belén
  • García-García, Isabel
  • Gazol Burgos, Antonio
  • Camarero, Jesús Julio
  • González de Andrés, Ester
  • Colangelo, Michele
  • Valeriano, Cristina
  • Gallego, Francisco Javier
  • Linares, Juan Carlos
Local differentiation at distribution limits may influence species' adaptive capacity to environmental changes. However, drivers, such gene flow and local selection, are still poorly understood. We focus on the role played by range limits in mountain forests to test the hypothesis that relict tree populations are subjected to genetic differentiation and local adaptation. Two alpine treelines of mountain pine (Pinus uncinata Ram. ex DC) were investigated in the Spanish Pyrenees. Further, an isolated relict population forming the species' southernmost distribution limit in north-eastern Spain was also investigated. Using genotyping by sequencing, a genetic matrix conformed by single nucleotide polymorphisms (SNPs) was obtained. This matrix was used to perform genotype-environment and genotype-phenotype associations, as well as to model risk of non-adaptedness. Increasing climate seasonality appears as an essential element in the interpretation of SNPs subjected to selective pressures. Genetic differentiations were overall weak. The differences in leaf mass area and radial growth rate, as well as the identification of several SNPs subjected to selective pressures, exceeded neutral predictions of differentiation among populations. Despite genetic drift might prevail in the isolated population, the Fst values (0.060 and 0.066) showed a moderate genetic drift and Nm values (3.939 and 3.555) indicate the presence of gene flow between the relict population and both treelines. Nonetheless, the SNPs subjected to selection pressures provide evidences of possible selection in treeline ecotones. Persistence in range boundaries seems to involve several selective pressures in species' traits, which were significantly related to enhanced drought seasonality at the limit of P. uncinata distribution range. We conclude that gene flow is unlikely to constrain adaptation in the P. uncinata rear edge, although this species shows vulnerability to future climate change scenarios involving warmer and drier conditions., Belén Méndez-Cea is recipient of a UCM Santander predoctoral fellowship (CT42/18-CT43/18), Isabel García-García is recipient of a predoctoral fellowship (FPU18/01153). This research was funded by projects LMP242_18 (Gobierno de Aragón, co-financed by FEDER European Funds), FORMAL (ref. RTI2018–096884-B-C31; Spanish Ministry of Science, Innovation and Universities) and the project “CLU-2019–05 – IRNASA/CSIC Unit of Excellence”, funded by the Junta de Castilla y León and co-financed by the European Union (ERDF “Europe drives our growth”)., Peer reviewed
 

DOI: http://hdl.handle.net/10261/345131
Digital.CSIC. Repositorio Institucional del CSIC
oai:digital.csic.es:10261/345131

HANDLE: http://hdl.handle.net/10261/345131
Digital.CSIC. Repositorio Institucional del CSIC
oai:digital.csic.es:10261/345131
 
Ver en: http://hdl.handle.net/10261/345131
Digital.CSIC. Repositorio Institucional del CSIC
oai:digital.csic.es:10261/345131

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